Leonard, Gene F. and Goodroe, John R. "More on extensible machines" pp183-188

[ACM] (1966) [ACM] CACM 9(03) March 1966 includes proceedings of the ACM Programming Languages and Pragmatics Conference, San Dimas, California, August 1965  

Languages mentioned CL-II {1961} Compiler generator language TR4 {1964} Extensible compiler generator system for the Telefunken TR4 Computer