Allen, F. E. "The history of language processor technology in IBM" pp535-548.

[IBM] (1981) IBM Journal of Research and Development, 25(5), September 1981 25th anniversary issue  

Languages mentioned APL {1960} Array-centered programing language COBOL {1960} COmmon Business Oriented Language FORMAC {1962} FORmula MAnipulation Compiler PL/I {1964} Programming Language One RPG {1959} Report Program Generator SPEEDCODING {1953} Backus Autocoder