The Securities and Exchange Commission has not necessarily reviewed the information in this filing and has not determined if it is accurate and complete.
The reader should not assume that the information is accurate and complete.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
FORM 13F

FORM 13F INFORMATION TABLE
OMB APPROVAL
OMB Number: 3235-0006
Estimated average burden
hours per response: 23.8
COLUMN 1 COLUMN 2 COLUMN 3 COLUMN 4 COLUMN 5 COLUMN 6 COLUMN 7 COLUMN 8
VALUE SHRS OR SH/ PUT/ INVESTMENT OTHER VOTING AUTHORITY
NAME OF ISSUER TITLE OF CLASS CUSIP (x$1000) PRN AMT PRN CALL DISCRETION MANAGER SOLE SHARED NONE
3M Company COM 88579y101 286 2,021 SH   SOLE   0 0 2,021
58.com Inc ADR COM 31680q104 36,247 973,085 SH   SOLE   957,040 0 16,045
AT&T Inc COM 00206r102 204 5,780 SH   SOLE   0 0 5,780
Acacia Conservation Fund COM 003993144 141 140,516 SH   SOLE   0 0 140,516
Advance Auto Parts COM 00751y106 218,019 1,673,207 SH   SOLE   1,104,665 0 568,542
Allstate COM 020002101 736 12,000 SH   SOLE   0 0 12,000
Altria Group Inc COM 02209S103 3,913 85,174 SH   SOLE   2,664 0 82,510
American Electric Power COM 025537101 805 15,420 SH   SOLE   0 0 15,420
American Express COM 025816109 122,469 1,399,011 SH   SOLE   574,647 0 824,364
Amgen COM 031162100 227 1,617 SH   SOLE   0 0 1,617
Apple Computer COM 037833100 1,382 13,720 SH   SOLE   0 0 13,720
Applied Materials COM 038222105 296 13,692 SH   SOLE   0 0 13,692
Arch Capital Group Ltd COM g0450a105 590 10,788 SH   SOLE   0 0 10,788
Athenahealth Inc. COM 04685w103 26,338 200,000 SH   SOLE   200,000 0 0
Automatic Data Processing COM 053015103 506 6,091 SH   SOLE   0 0 6,091
BP Amoco PLC ADR COM 055622104 244 5,548 SH   SOLE   0 0 5,548
Bank of America Corp COM 060505104 9,174 538,077 SH   SOLE   500,732 0 37,345
Bed Bath & Beyond Inc COM 075896100 400 6,080 SH   SOLE   0 0 6,080
Berkshire Hathaway - Cl A COM 084670108 2,115,139 10,223 SH   SOLE   6,880 0 3,343
Berkshire Hathaway - Cl B COM 084670702 679,162 4,916,475 SH   SOLE   3,090,039 0 1,826,436
Best Buy Company Inc COM 086516101 336 10,000 SH   SOLE   0 0 10,000
Bio-Techne Corp COM 09073m104 238 2,540 SH   SOLE   0 0 2,540
Boeing COM 097023105 224 1,756 SH   SOLE   0 0 1,756
Brown & Brown Inc. COM 115236101 85,140 2,648,208 SH   SOLE   1,958,575 0 689,633
CVS Corp. COM 126650100 2,113 26,553 SH   SOLE   0 0 26,553
Cabelas Inc. Cl A COM 126804301 201,123 3,414,658 SH   SOLE   2,255,641 0 1,159,017
Canadian Natural Resources COM 136385101 29,484 759,123 SH   SOLE   485,472 0 273,651
Caterpillar COM 149123101 6,820 68,871 SH   SOLE   54,422 0 14,449
Central Securities Corp COM 155123102 394 17,128 SH   SOLE   0 0 17,128
ChevronTexaco Corp COM 166764100 716 5,998 SH   SOLE   89 0 5,909
Chubb COM 171232101 1,086 11,922 SH   SOLE   0 0 11,922
Citigroup Inc COM 172967424 451 8,706 SH   SOLE   40 0 8,666
Coca Cola Co. COM 191216100 44,487 1,042,818 SH   SOLE   523,195 0 519,623
Colfax Corp COM 194014106 28,565 501,400 SH   SOLE   500,000 0 1,400
Colgate Palmolive Co. COM 194162103 231 3,548 SH   SOLE   0 0 3,548
Comcast Corp. Spl Cl A COM 20030n200 400 7,474 SH   SOLE   0 0 7,474
Concur Technologies Inc COM 206708109 1,138 8,974 SH   SOLE   5,128 0 3,846
ConocoPhillips COM 20825c104 6,047 79,026 SH   SOLE   78,000 0 1,026
Costco Wholesale Corp COM 22160k105 92,699 739,699 SH   SOLE   305,469 0 434,230
Cresud SACIFYA Spon ADR Repstg COM 226406106 6,597 605,247 SH   SOLE   605,247 0 0
Daimler-Chrysler AG COM d1668r123 295 3,864 SH   SOLE   0 0 3,864
Danaher Corp. COM 235851102 111,486 1,467,303 SH   SOLE   1,067,684 0 399,619
Devon Energy Corporation New COM 25179m103 249 3,645 SH   SOLE   0 0 3,645
Diageo PLC Sponsored ADR COM 25243q205 3,722 32,250 SH   SOLE   30,250 0 2,000
DirectTV COM 25490a309 3,708 42,854 SH   SOLE   33,659 0 9,195
Disney Walt COM 254687106 5,108 57,374 SH   SOLE   0 0 57,374
Dow Chemical COM 260543103 2,150 41,000 SH   SOLE   0 0 41,000
Du Pont E I De Nemours & Co. COM 263534109 4,360 60,762 SH   SOLE   51,768 0 8,994
Ebay Inc COM 278642103 214 3,785 SH   SOLE   0 0 3,785
Edison International COM 281020107 2,399 42,900 SH   SOLE   0 0 42,900
Emcor Group Inc COM 29084q100 66,452 1,662,959 SH   SOLE   1,139,757 0 523,202
Emerson Electric COM 291011104 337 5,380 SH   SOLE   0 0 5,380
Energizer Holdings Inc COM 29266r108 203 1,644 SH   SOLE   223 0 1,421
Expeditors Int'l of Wash. Inc. COM 302130109 5,581 137,524 SH   SOLE   77,753 0 59,771
Express Scripts Holding Co. COM 30219g108 379 5,372 SH   SOLE   0 0 5,372
Exxon Mobil Corp COM 30231g103 8,346 88,742 SH   SOLE   14,146 0 74,596
Fastenal Co COM 311900104 1,081,482 24,086,459 SH   SOLE   15,561,917 0 8,524,542
Fifth Third Bancorp COM 316773100 2,292 114,508 SH   SOLE   0 0 114,508
General Electric COM 369604103 6,203 242,101 SH   SOLE   46,112 0 195,989
General Mills COM 370334104 5,074 100,567 SH   SOLE   100,040 0 527
Goldman Sachs Group Inc COM 38141g104 232,325 1,265,593 SH   SOLE   862,833 0 402,760
Google Inc Cl A COM 38259p508 346,259 588,466 SH   SOLE   425,943 0 162,523
Google Inc Cl C COM 38259p706 341,615 591,684 SH   SOLE   427,785 0 163,899
Graham Holdings Co. COM 384637104 2,272 3,248 SH   SOLE   2,000 0 1,248
Greenlight Capital Re Ltd Cl A COM G4095J109 14,318 441,764 SH   SOLE   441,764 0 0
Groupon Inc. COM 399473107 20,049 3,001,417 SH   SOLE   3,000,000 0 1,417
HDFC Bank Ltd ADR Repstg 3 Shs COM 40415f101 846 18,166 SH   SOLE   0 0 18,166
Heartland Express COM 422347104 2,421 101,057 SH   SOLE   0 0 101,057
Hexcel Corp COM 428291108 46,897 1,181,280 SH   SOLE   1,181,280 0 0
Home Depot COM 437076102 2,642 28,796 SH   SOLE   159 0 28,637
IAC Interactivecorp COM 44919p300 79,094 1,200,210 SH   SOLE   1,200,000 0 210
IBM COM 459200101 268,724 1,415,603 SH   SOLE   923,127 0 492,476
ITAU Unibanco Holdings S.A. AD COM 465562106 197 14,168 SH   SOLE   0 0 14,168
Idex Corp COM 45167R104 578 7,985 SH   SOLE   0 0 7,985
Idexx Laboratories Corp. COM 45168D104 612,372 5,197,081 SH   SOLE   3,413,943 0 1,783,138
Illinois Tool Works COM 452308109 200 2,374 SH   SOLE   80 0 2,294
Innerworkings Inc Com COM 45773y105 8,090 1,000,000 SH   SOLE   1,000,000 0 0
Intel Corp COM 458140100 610 17,511 SH   SOLE   0 0 17,511
Interactive Brokers Group Inc COM 45841n107 43,320 1,736,264 SH   SOLE   1,729,299 0 6,965
Ishares India 50 ETF COM 464289529 264 8,910 SH   SOLE   0 0 8,910
JC Penney COM 708160106 241 24,000 SH   SOLE   0 0 24,000
JP Morgan Chase & Co. COM 46625h100 3,030 50,299 SH   SOLE   996 0 49,303
Jacobs Engineering Group Inc COM 469814107 192,127 3,935,406 SH   SOLE   2,574,319 0 1,361,087
Johnson & Johnson COM 478160104 8,128 76,259 SH   SOLE   60,549 0 15,710
Kellogg Co. COM 487836108 2,372 38,500 SH   SOLE   38,500 0 0
Kinder Morgan Energy Partners COM 494550106 224 2,400 SH   SOLE   0 0 2,400
Kraft Foods Group Inc. COM 50076Q106 1,024 18,158 SH   SOLE   614 0 17,544
Lennox International Inc. COM 526107107 1,505 19,584 SH   SOLE   1,814 0 17,770
Leucadia Nat'l COM 527288104 405 16,971 SH   SOLE   2,482 0 14,489
Linear Technology Group COM 535678106 6,045 136,184 SH   SOLE   44,855 0 91,329
Lockheed Martin Corp. COM 539830109 503 2,750 SH   SOLE   0 0 2,750
Lowe's Companies COM 548661107 546 10,314 SH   SOLE   0 0 10,314
MRC Global Inc. COM 55345k103 8,675 372,000 SH   SOLE   372,000 0 0
Mastercard Inc COM 57636q104 402,577 5,446,115 SH   SOLE   4,026,880 0 1,419,235
McDonalds COM 580135101 13,040 137,542 SH   SOLE   89,321 0 48,221
McGraw Hill COM 580645109 42,709 505,730 SH   SOLE   500,000 0 5,730
Medtronic Inc COM 585055106 601 9,700 SH   SOLE   0 0 9,700
Merck & Co. COM 58933y105 284 4,784 SH   SOLE   309 0 4,475
Microsoft COM 594918104 2,935 63,309 SH   SOLE   15,276 0 48,033
Mohawk Industries COM 608190104 381,639 2,830,730 SH   SOLE   1,967,669 0 863,061
Mondelez International COM 50075n104 1,943 56,710 SH   SOLE   1,843 0 54,867
Novartis AG - Sponsored ADR COM 66987v109 732 7,772 SH   SOLE   0 0 7,772
Novo Nordisk A/S ADR COM 670100205 3,602 75,642 SH   SOLE   43,250 0 32,392
O Reilly Automotive Inc COM 67103h107 546,427 3,634,125 SH   SOLE   2,730,825 0 903,300
Omnicom Group COM 681919106 197,559 2,868,999 SH   SOLE   1,923,549 0 945,450
Oracle Corp. COM 68389X105 66,992 1,750,063 SH   SOLE   1,728,875 0 21,188
PepsiCo COM 713448108 17,577 188,815 SH   SOLE   130,954 0 57,861
Perrigo Co PLC COM G97822103 256,931 1,710,706 SH   SOLE   1,085,266 0 625,440
Pfizer COM 717081103 324 10,967 SH   SOLE   0 0 10,967
Philip Morris Intl Inc. COM 718172109 7,937 95,165 SH   SOLE   3,738 0 91,427
Phillips 66 COM 718546104 3,211 39,491 SH   SOLE   39,000 0 491
Pioneer Natural Resources Co. COM 723787107 34,451 174,903 SH   SOLE   171,000 0 3,903
Praxair COM 74005P104 244,139 1,892,547 SH   SOLE   1,255,008 0 637,539
Precision Castparts Corp COM 740189105 725,954 3,064,648 SH   SOLE   1,945,670 0 1,118,978
Price T Rowe Group Inc COM 74144t108 317 4,045 SH   SOLE   0 0 4,045
Primerica Inc COM 74164M108 179,431 3,721,085 SH   SOLE   3,705,000 0 16,085
Procter & Gamble COM 742718109 14,346 171,316 SH   SOLE   45,500 0 125,816
Progressive Corp. Ohio COM 743315103 1,642 64,940 SH   SOLE   0 0 64,940
Public Storage Inc. COM 74460d109 413 2,493 SH   SOLE   0 0 2,493
Qihoo 360 Technology Co. ADR COM 74734m109 101,205 1,500,000 SH   SOLE   1,500,000 0 0
Qualcomm Inc COM 747525103 22,609 302,382 SH   SOLE   300,000 0 2,382
Range Resources Corp COM 75281a109 244,607 3,607,242 SH   SOLE   3,601,850 0 5,392
Republic Services Inc Cl A COM 760759100 492 12,606 SH   SOLE   714 0 11,892
Resource America Inc - (RESTRI COM 761195205 2,738 294,117 SH   SOLE   294,117 0 0
Resource America Inc Cl A COM 761195205 5,616 603,180 SH   SOLE   603,180 0 0
Ritchie Bros Auctioneers Inc COM 767744105 29,648 1,324,170 SH   SOLE   895,524 0 428,646
Robert Half Internat'l COM 770323103 343 7,000 SH   SOLE   0 0 7,000
Roper Industries Inc New COM 776696106 653 4,465 SH   SOLE   0 0 4,465
Royal Bk CDA Montreal Que COM 780087102 3,601 50,400 SH   SOLE   50,400 0 0
Royal Dutch Shell PLC Spon ADR COM 780259206 1,621 21,299 SH   SOLE   7,199 0 14,100
SEI Investments Co COM 784117103 362 10,000 SH   SOLE   0 0 10,000
Schlumberger Ltd COM 806857108 6,563 64,536 SH   SOLE   58,000 0 6,536
Sherwin Williams Co. COM 824348106 1,162 5,307 SH   SOLE   106 0 5,201
Sirona Dental Systems Inc COM 82966c103 217,287 2,833,679 SH   SOLE   2,009,232 0 824,447
Soufun Holdings LTD ADR COM 836034108 1,990 200,000 SH   SOLE   200,000 0 0
Southwestern Energy Co COM 845467109 124,647 3,566,435 SH   SOLE   3,558,000 0 8,435
Stericycle Inc. COM 858912108 350 3,000 SH   SOLE   0 0 3,000
Suntrust Banks COM 867914103 1,187 31,203 SH   SOLE   0 0 31,203
TJX Cos - New COM 872540109 1,794,776 30,332,526 SH   SOLE   19,428,904 0 10,903,622
Thermo Electron COM 883556102 377 3,101 SH   SOLE   0 0 3,101
Tiffany & Co COM 886547108 206,872 2,147,983 SH   SOLE   1,507,276 0 640,707
Travelers Companies Inc. COM 89417e109 212 2,262 SH   SOLE   0 0 2,262
Trimble Navigation Ltd. COM 896239100 104,080 3,412,462 SH   SOLE   2,382,338 0 1,030,124
U.S. Bancorp New - Del. COM 902973304 1,190 28,452 SH   SOLE   0 0 28,452
Union Pacific COM 907818108 10,934 100,846 SH   SOLE   0 0 100,846
United Technologies COM 913017109 215 2,033 SH   SOLE   0 0 2,033
Valeant Pharmaceuticals Intern COM 91911k102 4,525,615 34,494,015 SH   SOLE   21,538,500 0 12,955,515
Verisk Analytics Class A COM 92345Y106 3,616 59,380 SH   SOLE   21,546 0 37,834
Verizon Communications COM 92343v104 355 7,109 SH   SOLE   0 0 7,109
Visa Inc Class A COM 92826C839 238,035 1,115,595 SH   SOLE   599,402 0 516,193
WPP PLC New ADR COM 92937a102 314 3,124 SH   SOLE   0 0 3,124
Wal-Mart Stores COM 931142103 168,987 2,209,841 SH   SOLE   1,691,161 0 518,680
Waters Corp COM 941848103 203,253 2,050,578 SH   SOLE   1,416,668 0 633,910
Wells Fargo & Co. New COM 949746101 15,277 294,530 SH   SOLE   150,300 0 144,230
West Pharmaceutical Svcs Inc C COM 955306105 46,034 1,028,465 SH   SOLE   658,023 0 370,442
World Fuel Services Corp COM 981475106 236,567 5,926,035 SH   SOLE   4,541,907 0 1,384,128
Yandex NV Shs COM n97284108 55,591 2,000,048 SH   SOLE   2,000,000 0 48
Young Broadcasting Inc Cl A COM 987434107 0 144,865 SH   SOLE   0 0 144,865
Zoetis Inc. COM 98978v103 6,404 173,322 SH   SOLE   51,134 0 122,188
Constellation Software Inc. COM 21037x100 64,692 256,800 SH   SOLE   256,800 0 0
Jardine Matheson Hldgs (U$.25 COM G50736100 223 3,600 SH   SOLE   3,600 0 0
Ryanair Hldgs PLC Spon ADR COM 783513104 458 8,121 SH   SOLE   780 0 7,341