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Priority claimed from US07/203,975external-prioritypatent/US4868242A/en
Priority claimed from US07/203,959external-prioritypatent/US4866128A/en
Priority claimed from US07/239,094external-prioritypatent/US4904728A/en
Priority claimed from US07/239,095external-prioritypatent/USH1278H/en
Application filed by Shell Int ResearchfiledCriticalShell Int Research
Priority claimed from EP89201338Aexternal-prioritypatent/EP0345854B1/de
Application grantedgrantedCritical
Publication of ATE98978T1publicationCriticalpatent/ATE98978T1/de