Sapper, Gerd R. "The programming language PS440 as a tool for implementing a time-sharing system"

[LSI 1971] (1971) [ACM] SIGPLAN Notices 6(10) October 1971 Proceedings of the SIGPLAN symposium on Languages for system implementation 1971, Lafayette, Indiana, United States; October, 1971  

Languages mentioned PS 440 {1974} PL 360 for the Telefunken TR 440 TAS {1971} Telefunken-Assembler-Sprache