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

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COLUMN 1COLUMN 2COLUMN 3COLUMN 4COLUMN 5COLUMN 6COLUMN 7COLUMN 8
VALUESHRS ORSH/PUT/INVESTMENTOTHERVOTING AUTHORITY
NAME OF ISSUERTITLE OF CLASSCUSIP(x$1000)PRN AMTPRNCALLDISCRETIONMANAGERSOLESHAREDNONE
BARCLAYS BK PLC CONV ZERO CPNConvertible Bonds06741JV894646,000PRN SOLE046,00000
APPLE INC.Common Stocks03783310029,407240,748SH  SOLE0240,74800
ABB LIMITEDCommon Stocks00037520415,534509,822SH  SOLE0509,82200
ACCENTURE PLCCommon StocksG1151C10111,08840,139SH  SOLE040,13900
AMGEN INCCommon Stocks0311621003821,534SH  SOLE01,53400
AMAZON COM INCCommon Stocks023135106885286SH  SOLE028600
ACTIVISION BLIZZARD, INC.Common Stocks00507V10919,276207,274SH  SOLE0207,27400
BALLARD POWER SYSTEMSCommon Stocks05858610829812,226SH  SOLE012,22600
BRISTOL-MYERS SQUIBB COCommon Stocks11012210825,735407,646SH  SOLE0407,64600
BERKSHIRE HATHAWAY CLASS BCommon Stocks0846707022871,125SH  SOLE01,12500
BLACK STONE MINERALS LPCommon Stocks09225M10110,1341,162,175SH  SOLE01,162,17500
ANHEUSER-BUSCH INBEV SACommon Stocks03524A10817,157272,977SH  SOLE0272,97700
BLACKSTONE GROUP LPCommon Stocks09260D1072162,900SH  SOLE02,90000
CHECK POINT SOFTWARE TECHCommon StocksM2246510410,08490,064SH  SOLE090,06400
DORCHESTER MINERALS LPCommon Stocks25820R10546333,880SH  SOLE033,88000
EBAY INCCommon Stocks27864210316,964277,009SH  SOLE0277,00900
ENTERPRISE PRODUCTS PRTNSCommon Stocks29379210725,5171,158,831SH  SOLE01,158,83100
GILEAD SCIENCES, INCCommon Stocks37555810317,441269,852SH  SOLE0269,85200
GAMING AND LEISURE PROPERTIES INC.Common Stocks36467J10896722,794SH  SOLE022,79400
ALPHABET INC CL C (GOOGLE C)Common Stocks02079K10752,85125,549SH  SOLE025,54900
ALPHABET INC CL A (GOOGLE A)Common Stocks02079K30528,50613,821SH  SOLE013,82100
HONEYWELL INTL INCCommon Stocks4385161062,46211,340SH  SOLE011,34000
INDEPENDENT BANK GROUP, INCCommon Stocks45384B1062022,800SH  SOLE02,80000
INOVALON HOLDINGS INC. (Class A)Common Stocks45781D10112,978450,939SH  SOLE0450,93900
JP MORGAN CHASE & COCommon Stocks46625H1002301,509SH  SOLE01,50900
KINDER MORGAN, INC.Common Stocks49456B10122,6441,360,008SH  SOLE01,360,00800
LIBERTY MEDIA - SIRIUSXM CL CCommon Stocks53122960712,632286,369SH  SOLE0286,36900
LAS VEGAS SANDSCommon Stocks51783410712,376203,684SH  SOLE0203,68400
MICROSOFT CORPORATIONCommon Stocks5949181044311,829SH  SOLE01,82900
MATADOR RESOURCES CO.Common Stocks5764852051,05545,000SH  SOLE045,00000
NIELSEN HOLDINGS PLCCommon StocksG6518L10819,245765,198SH  SOLE0765,19800
NVIDIA CORPCommon Stocks67066G1045341,000SH  SOLE01,00000
NXP SEMICONDUCTCommon StocksN6596X1092,09410,400SH  SOLE010,40000
OWENS & MINOR, INC.Common Stocks6907321022446,500SH  SOLE06,50000
PAYCHEX INC.Common Stocks7043261075765,881SH  SOLE05,88100
HEALTHPEAK PROPERTIES, INC.Common Stocks42250P1032,62582,698SH  SOLE082,69800
PEPSICO INCCommon Stocks7134481082751,944SH  SOLE01,94400
PFIZER INCCommon Stocks7170811032216,107SH  SOLE06,10700
QUALCOMM INCCommon Stocks74752510334,131257,417SH  SOLE0257,41700
ROYAL DUTCH SHELL PLC ADR CL BCommon Stocks78025910720,183547,991SH  SOLE0547,99100
REATA PHARMACEUTICALS INC.Common Stocks75615P1032562,565SH  SOLE02,56500
RAYTHEON TECHNOLOGIES CORP.Common Stocks75513E10115,100195,421SH  SOLE0195,42100
SPROUTS FARMERS MARKET INCCommon Stocks85208M10216,972637,574SH  SOLE0637,57400
SPIRIT AEROSYSTEMSCommon Stocks84857410923,797489,151SH  SOLE0489,15100
SPDR S & P 500 ETFCommon Stocks78462F1034361,100SH  SOLE01,10000
TESLA MOTORS INC.Common Stocks88160R101227340SH  SOLE034000
UNITEDHEALTH GROUP INC.Common Stocks91324P10221,43957,621SH  SOLE057,62100
VISA, INC.Common Stocks92826C8397123,362SH  SOLE03,36200
XYLEM INC.Common Stocks98419M10015,080143,374SH  SOLE0143,37400