WO9501232-A1 -- EP312174-A   HYDRACONSULT BV (HYDR-Non-standard);  GEO KINETICS BV (GEOK-Non-standard)   POOL W;  EP403895-A   PROCUREMENT & PROJ (PROC-Non-standard);  UWA UMWELTANAL YBIC GMBH (UWAU-Non-standard)   DOERING F R,  DECRISTOFO P;  EP504551-A2   PROCUREMENT & PROJECTS GMBH (PROC-Non-standard);  US5074986-A   MASSACHUSETTS INST TECHNOLOGY (MASI)   PROBSTEIN R F,  RENAUD P C,  SHAPIRO A P;  US5137608-A   ;  WO1991001392-A   ;  US5476992-A -- EP312174-A   HYDRACONSULT BV (HYDR-Non-standard);  GEO KINETICS BV (GEOK-Non-standard)   POOL W;  EP504551-A2   PROCUREMENT & PROJECTS GMBH (PROC-Non-standard);  US4067389-A   MOBIL OIL CORP (MOBI)   SAVINS J G;  US4378845-A   MOBIL OIL CORP (MOBI)   MEDLIN W L,  MULLINS L D,  ZUMWALT G L;  US4964466-A   EXXON CHEM PATENTS INC (ESSO)   PIGOTT J M,  WILLIAMS D A,  NEWLOVE J C;  US5009797-A   WEYERHAEUSER CO (WEYE)   PENNY G S,  STEPHENS R S,  WINSLOW A R;  US5057227-A   UNIV S CAROLINA (UYSC-Non-standard)   COHEN A D;  US5074986-A   MASSACHUSETTS INST TECHNOLOGY (MASI)   PROBSTEIN R F,  RENAUD P C,  SHAPIRO A P;  US5098538-A   ;  US5106233-A   BREAUX L (BREA-Individual)   BREAUX L;  US5135058-A   MILLGARD ENVIRONMEN (MILL-Non-standard)   MILLGARD V D,  KAPPLER R H;  US5137608-A   ;  US5181796-A   DEYOUNG S H (DEYO-Individual)   DEYOUNG S H;  US5193934-A   SHELL OIL CO (SHEL)   JOHNSON P C,  WEINGAERTNER D A;  WO1991001392-A   ;  WO1991008176-A   ;  WO1992006802-A1   ;  WO1992019545-A1   ;  WO1992019556-A1   ;  AU696030-B -- US5074986-A   MASSACHUSETTS INST TECHNOLOGY (MASI)   PROBSTEIN R F,  RENAUD P C,  SHAPIRO A P;  US5137608-A   ;  EP706427-B1 -- EP312174-A   HYDRACONSULT BV (HYDR-Non-standard);  GEO KINETICS BV (GEOK-Non-standard)   POOL W;  EP403895-A   PROCUREMENT & PROJ (PROC-Non-standard);  UWA UMWELTANAL YBIC GMBH (UWAU-Non-standard)   DOERING F R,  DECRISTOFO P;  EP504551-A2   PROCUREMENT & PROJECTS GMBH (PROC-Non-standard);  US5074986-A   MASSACHUSETTS INST TECHNOLOGY (MASI)   PROBSTEIN R F,  RENAUD P C,  SHAPIRO A P;  US5137608-A   ;  WO1991001392-A