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
3D SYSTEMS CORP COM 88554D205 58,162 1,769,457 SH   SOLE   1,769,457 0 0
3M CO COM 88579Y101 701 4,265 SH   SOLE   4,265 0 0
ABBOTT LABORATORIES COM 002824100 513 11,400 SH   SOLE   11,400 0 0
ABBVIE INC COM 00287Y109 570 8,716 SH   SOLE   8,716 0 0
ALTERA CORP COM 021441100 259 7,018 SH   SOLE   7,018 0 0
AMAZON.COM INC COM 023135106 250 805 SH   SOLE   805 0 0
AMBER ROAD INC COM 02318y108 979 95,749 SH   SOLE   95,749 0 0
AMERICAN ADDICTION CENTERS COM 000307108 2,587 83,675 SH   SOLE   83,675 0 0
AMERICAN TOWER CORP COM 03027X100 68,775 695,748 SH   SOLE   695,748 0 0
ANADARKO PETROLEUM CORP COM 032511107 437 5,300 SH   SOLE   5,300 0 0
ANSYS INC COM 03662Q105 175,274 2,137,484 SH   SOLE   2,137,484 0 0
APPLE COMPUTER INC COM 037833100 1,369 12,403 SH   SOLE   12,403 0 0
APPLIED MINERALS COM 03823m100 58 80,000 SH   SOLE   80,000 0 0
ATRION CORP COM 049904105 2,458 7,229 SH   SOLE   7,229 0 0
AUTOMATIC DATA PROCESSING COM 053015103 2,129 25,532 SH   SOLE   25,532 0 0
BECTON DICKINSON & CO COM 075887109 306 2,200 SH   SOLE   2,200 0 0
BERKSHIRE HATHAWAY INC COM 084670108 1,582 7 SH   SOLE   7 0 0
BERKSHIRE HATHAWAY INC. DEL CL COM 084670702 3,560 23,710 SH   SOLE   23,710 0 0
BIO-TECHNE CORP COM 09073M104 44,364 480,134 SH   SOLE   480,134 0 0
BIOGEN IDEC INC COM 09062x103 41,947 123,573 SH   SOLE   123,573 0 0
BLACKBAUD INC COM 09227q100 14,095 325,828 SH   SOLE   325,828 0 0
CANADIAN NATIONAL RAILROAD CO COM 136375102 1,378 20,000 SH   SOLE   20,000 0 0
CAPITAL ONE FINANCIAL COM 14040H105 2,163 26,201 SH   SOLE   26,201 0 0
CARMAX INC COM 143130102 106,580 1,600,778 SH   SOLE   1,600,778 0 0
CELGENE CORP COM 151020104 117,980 1,054,708 SH   SOLE   1,054,708 0 0
CHEVRON CORP COM 166764100 1,134 10,109 SH   SOLE   10,109 0 0
CHIPOTLE MEXICAN GRILLE INC COM 169656105 19,175 28,013 SH   SOLE   28,013 0 0
CISCO SYSTEMS INC COM 17275R102 2,267 81,491 SH   SOLE   81,491 0 0
COCA COLA CO COM 191216100 1,147 27,162 SH   SOLE   27,162 0 0
COGNIZANT TECH SOLUTIONS CORP COM 192446102 211 4,000 SH   SOLE   4,000 0 0
COLGATE-PALMOLIVE COM 194162103 692 10,000 SH   SOLE   10,000 0 0
COMCAST CORP - A COM 20030N101 732 12,625 SH   SOLE   12,625 0 0
COMCAST CORP - A - SPL COM 20030N200 4,188 72,744 SH   SOLE   72,744 0 0
CONCHO RESOURCES INC COM 20605P101 77,878 780,735 SH   SOLE   780,735 0 0
CORE LABORATORIES NV COM N22717107 67,751 562,993 SH   SOLE   562,993 0 0
COSTAR GROUP INC. COM 22160n109 103,284 562,458 SH   SOLE   562,458 0 0
CROWN CASTLE INTL CORP COM 22822V101 5,135 65,249 SH   SOLE   65,249 0 0
DEALERTRACK TECHNOLOGIES INC COM 242309102 74,853 1,689,298 SH   SOLE   1,689,298 0 0
DEERE & CO COM 244199105 228 2,573 SH   SOLE   2,573 0 0
DENTSPLY INTL COM 249030107 250 4,700 SH   SOLE   4,700 0 0
DISCOVER FINANCIAL SERVICES COM 254709108 112,016 1,710,424 SH   SOLE   1,710,424 0 0
DONALDSON INC COM 257651109 1,805 46,733 SH   SOLE   46,733 0 0
DORMAN PRODUCTS INC COM 258278100 368 7,616 SH   SOLE   7,616 0 0
DOUGLAS DYNAMICS INC COM 25960R105 787 36,714 SH   SOLE   36,714 0 0
DUKE REALTY CORP COM 264411505 304 15,050 SH   SOLE   15,050 0 0
EAST WEST BANCORP INC COM 27579R104 329 8,500 SH   SOLE   8,500 0 0
ECOLAB INC COM 278865100 116,597 1,115,549 SH   SOLE   1,115,549 0 0
ELI LILLY & CO COM 532457108 659 9,554 SH   SOLE   9,554 0 0
ELLIE MAE INC COM 28849P100 2,322 57,591 SH   SOLE   57,591 0 0
EMERSON COM 291011104 486 7,876 SH   SOLE   7,876 0 0
ENTERPRISE PRODUCTS PARTNERS L COM 293792107 645 17,850 SH   SOLE   17,850 0 0
ENVESTNET INC COM 29404K106 1,099 22,360 SH   SOLE   22,360 0 0
EQT CORPORATION COM 26884L109 3,770 49,806 SH   SOLE   49,806 0 0
EQUITY RESIDENTIAL PROPERTYS I COM 29476l107 559 7,776 SH   SOLE   7,776 0 0
EXAMWORKS GROUP INC. COM 30066a105 78,887 1,896,776 SH   SOLE   1,896,776 0 0
EXPEDITORS INTERNATIONAL COM 302130109 46,661 1,045,979 SH   SOLE   1,045,979 0 0
EXPONENT INC. COM 30214U102 39,541 479,287 SH   SOLE   479,287 0 0
EXPRESS SCRIPTS INC COM 30219G108 1,667 19,685 SH   SOLE   19,685 0 0
EXXON MOBIL CORP COM 30231G102 1,726 18,666 SH   SOLE   18,666 0 0
FASTENAL CO COM 311900104 238,915 5,023,443 SH   SOLE   5,023,443 0 0
FINANCIAL ENGINES INC COM 317485100 54,447 1,489,668 SH   SOLE   1,489,668 0 0
FISERV INC COM 337738108 4,824 67,968 SH   SOLE   67,968 0 0
FORTINET INC COM 34959e109 1,074 35,030 SH   SOLE   35,030 0 0
FREEPORT MCMORAN COPPER & GOLD COM 35671D857 304 13,014 SH   SOLE   13,014 0 0
GENERAL ELECTRIC COM 369604103 3,135 124,074 SH   SOLE   124,074 0 0
GENUINE PARTS COMPANY COM 372460105 320 2,999 SH   SOLE   2,999 0 0
GILEAD SCIENCES INC. COM 375558103 720 7,642 SH   SOLE   7,642 0 0
GOOGLE INC CL C COM 38259P706 237 450 SH   SOLE   450 0 0
GOOGLE INC CLASS A COM 38259P508 239 450 SH   SOLE   450 0 0
GUIDEWIRE SOFTWARE INC COM 40171V100 364 7,191 SH   SOLE   7,191 0 0
HCP INC COM 40414L109 4,552 103,395 SH   SOLE   103,395 0 0
HEALTH CARE REIT INC COM 42217K106 234 3,086 SH   SOLE   3,086 0 0
HEALTHCARE SERVICES GROUP INC COM 421906108 64,241 2,076,969 SH   SOLE   2,076,969 0 0
HESS CORPORATION COM 42809h107 373 5,052 SH   SOLE   5,052 0 0
HOME DEPOT COM 437076102 315 2,999 SH   SOLE   2,999 0 0
ILLINOIS TOOL WORKS COM 452308109 227 2,400 SH   SOLE   2,400 0 0
ILLUMINA INC COM 452327109 31,140 168,706 SH   SOLE   168,706 0 0
IMAX CORP COM 45245E109 85,017 2,751,345 SH   SOLE   2,751,345 0 0
INTEL CORP COM 458140100 15,837 436,407 SH   SOLE   436,407 0 0
INTL BUSINESS MACH CORP COM 459200101 1,868 11,641 SH   SOLE   11,641 0 0
INTUITIVE SURGICAL INC COM 46120e602 56,634 107,071 SH   SOLE   107,071 0 0
INVENTURE FOODS INC COM 461212102 255 19,994 SH   SOLE   19,994 0 0
J P MORGAN CHASE & CO COM 46625H100 323 5,169 SH   SOLE   5,169 0 0
JACOBS ENGINEERING CP INC COM 469814107 5,509 123,277 SH   SOLE   123,277 0 0
JOHNSON & JOHNSON COM 478160104 10,995 105,145 SH   SOLE   105,145 0 0
LABORATORY CORP OF AMERICA HOL COM 50540R409 2,369 21,954 SH   SOLE   21,954 0 0
LINCOLN NATL CORP COM 534187109 319 5,536 SH   SOLE   5,536 0 0
LKQ CORP COM 501889208 153,821 5,470,162 SH   SOLE   5,470,162 0 0
LYNAS CORP LTD COM Q5683J103 4 75,000 SH   SOLE   75,000 0 0
M&T BANK CORP COM 55261F104 394 3,138 SH   SOLE   3,138 0 0
MACY'S, INC. COM 55616P104 307 4,663 SH   SOLE   4,663 0 0
MAGELLAN MIDSTREAM PARTNERS LP COM 559080106 298 3,600 SH   SOLE   3,600 0 0
MARKEL CORP COM 570535104 135,824 198,910 SH   SOLE   198,910 0 0
MASTERCARD INC CL A COM 57636Q104 2,167 25,150 SH   SOLE   25,150 0 0
McCORMICK & CO COM 579780206 892 12,000 SH   SOLE   12,000 0 0
MERCK & CO COM 58933Y105 1,167 20,550 SH   SOLE   20,550 0 0
MICROSOFT CORP COM 594918104 2,741 59,001 SH   SOLE   59,001 0 0
MIDDLEBY CORP COM 596278101 1,465 14,787 SH   SOLE   14,787 0 0
MONRO MUFFLER BRAKE COM 610236101 551 9,530 SH   SOLE   9,530 0 0
MOODYS CORP COM 615369105 121,194 1,264,943 SH   SOLE   1,264,943 0 0
NATIONAL AMERICAN UNIV HOLDING COM 63245Q105 40 15,000 SH   SOLE   15,000 0 0
NATIONAL INFORMATION CONSORTIU COM 62914b100 560 31,150 SH   SOLE   31,150 0 0
NEOGEN CORP COM 640491106 486 9,800 SH   SOLE   9,800 0 0
NESTLE S.A. COM 641069406 226 3,075 SH   SOLE   3,075 0 0
O REILLY AUTOMOTIVE INC COM 67103H107 20,978 108,908 SH   SOLE   108,908 0 0
ONEBEACON INSURANCE GP COM G67742109 502 30,969 SH   SOLE   30,969 0 0
OXYSURE SYSTEMS INC COM 69208t101 8 10,000 SH   SOLE   10,000 0 0
PANERA BREAD CO COM 69840W108 6,840 39,131 SH   SOLE   39,131 0 0
PAYCHEX COM 704326107 3,838 83,138 SH   SOLE   83,138 0 0
PEPSICO INC COM 713448108 385 4,069 SH   SOLE   4,069 0 0
PFIZER INC COM 717081103 1,172 37,633 SH   SOLE   37,633 0 0
PHILIP MORRIS INTL COM 718172109 382 4,694 SH   SOLE   4,694 0 0
PINNACLE WEST CAPITOL CORP COM 723484101 335 4,900 SH   SOLE   4,900 0 0
PNC FINANCIAL SVCS INC COM 693475105 2,369 25,965 SH   SOLE   25,965 0 0
POOL CORPORATION COM 73278L105 210 3,313 SH   SOLE   3,313 0 0
POTASH CORP OF SASKATCHEWAN COM 73755L107 26,561 752,007 SH   SOLE   752,007 0 0
PRECISION CASTPARTS CORP COM 740189105 434 1,800 SH   SOLE   1,800 0 0
PRICE SMART INC COM 741511109 59,535 652,653 SH   SOLE   652,653 0 0
PROCTER & GAMBLE CO COM 742718109 23,148 254,124 SH   SOLE   254,124 0 0
QUALCOMM INC COM 747525103 90,954 1,223,652 SH   SOLE   1,223,652 0 0
QUALITY DISTRIBUTION INC COM 74756m102 461 43,351 SH   SOLE   43,351 0 0
RANGE RESOURCES CORP COM 75281A109 38,114 713,068 SH   SOLE   713,068 0 0
RED HAT INC. COM 756577102 155,884 2,254,620 SH   SOLE   2,254,620 0 0
RENAISSANCE RE HOLDINGS LTD COM G7496G103 292 3,000 SH   SOLE   3,000 0 0
ROPER INDUSTRIES, INC COM 776696106 99,640 637,287 SH   SOLE   637,287 0 0
RPM INTERNATIONAL INC COM 749685103 208 4,100 SH   SOLE   4,100 0 0
SBA COMMUNICATIONS CORP COM 78388J106 1,604 14,485 SH   SOLE   14,485 0 0
SCHLUMBERGER LTD COM 806857108 42,959 502,971 SH   SOLE   502,971 0 0
SEI INVESTMENTS CO COM 784117103 149,505 3,733,896 SH   SOLE   3,733,896 0 0
SIGNET JEWELERS LTD COM g81276100 119,899 911,295 SH   SOLE   911,295 0 0
SILVER WHEATON CORP COM 828336107 305 15,000 SH   SOLE   15,000 0 0
SMITH & NEPHEW PLC COM 83175M205 276 7,500 SH   SOLE   7,500 0 0
SOTHERLY HOTELS, INC COM 83600C103 102 13,625 SH   SOLE   13,625 0 0
SOUTHWESTERN ENERGY CO COM 845467109 392 14,365 SH   SOLE   14,365 0 0
STERICYCLE INC COM 858912108 113,785 868,056 SH   SOLE   868,056 0 0
STRATASYS LTD COM M85548101 48,760 586,698 SH   SOLE   586,698 0 0
T ROWE PRICE GROUP INC COM 74144T108 16,576 193,061 SH   SOLE   193,061 0 0
TANGOE INC COM 87582Y108 45,423 3,486,009 SH   SOLE   3,486,009 0 0
TRIMBLE NAVIGATION LTD COM 896239100 109,304 4,118,470 SH   SOLE   4,118,470 0 0
TYLER TECHNOLOGIES INC COM 902252105 52,393 478,740 SH   SOLE   478,740 0 0
U.S. BANCORP COM 902973304 1,638 36,436 SH   SOLE   36,436 0 0
ULTIMATE SOFTWARE INC COM 90385d107 312 2,122 SH   SOLE   2,122 0 0
UNDER ARMOUR, INC COM 904311107 536 7,900 SH   SOLE   7,900 0 0
UNION PACIFIC CORP COM 907818108 292 2,450 SH   SOLE   2,450 0 0
UNITED TECHNOLOGIES CORP COM 913017109 468 4,071 SH   SOLE   4,071 0 0
VENTAS INC COM 92276f100 2,725 38,002 SH   SOLE   38,002 0 0
VERISK ANALYTICS COM 92345Y106 100,321 1,566,293 SH   SOLE   1,566,293 0 0
VERIZON COMMUNICATIONS COM 92343V104 203 4,329 SH   SOLE   4,329 0 0
VF CORP COM 918204108 300 4,000 SH   SOLE   4,000 0 0
VISA INC COM 92826C839 131,862 502,908 SH   SOLE   502,908 0 0
WAGEWORKS INC COM 930427109 127,350 1,972,274 SH   SOLE   1,972,274 0 0
WALT DISNEY CO COM 254687106 1,047 11,119 SH   SOLE   11,119 0 0
WASTE CONNECTIONS INC COM 941053100 78,562 1,785,911 SH   SOLE   1,785,911 0 0
WATSCO INC CL A COM 942622200 706 6,600 SH   SOLE   6,600 0 0
WELLS FARGO & CO COM 949746101 343 6,255 SH   SOLE   6,255 0 0
WHOLE FOODS MARKET COM 966837106 797 15,800 SH   SOLE   15,800 0 0
WR BERKLEY CORP COM 084423102 2,819 54,995 SH   SOLE   54,995 0 0
WSFS FINANCIAL CORPORATION COM 929328102 593 7,714 SH   SOLE   7,714 0 0
XOOM CORPORATION COM 98419Q101 1,532 87,519 SH   SOLE   87,519 0 0
ZOE'S KITCHEN INC COM 98979J109 314 10,500 SH   SOLE   10,500 0 0
ISHARES S&P 500 GROWTH INDEX ETFS 464287309 630 5,646 SH   SOLE   5,646 0 0
VANGUARD DIVIDEND ETFS 921908844 968 11,925 SH   SOLE   11,925 0 0
VANGUARD FTSE ALL-WORLD EX-US ETFS 922042775 2,594 55,347 SH   SOLE   55,347 0 0
VANGUARD FTSE EMERGING MARKETS ETFS 922042858 517 12,925 SH   SOLE   12,925 0 0
VANGUARD HIGH DIVIDEND YIELD E ETFS 921946406 340 4,950 SH   SOLE   4,950 0 0
VANGUARD INDEX REIT ETF ETFS 922908553 458 5,655 SH   SOLE   5,655 0 0