1. Steelman”, Requirements For High Order Computer Programming Languages, US Department of Defense, Washington D.C., June 1978
2. DIN 66 253 Teil 1: Basic-PEARL, Berlin 1978
3. DIN 66 253 Teil 2: Full-PEARL, Berlin 1980
4. Reference Manual for the Ada Programming Language, ANSI/M1L-STD-1815A, US Department of Defense, Washington D.C., January 1983
5. Ada9X Project Report, Ada9X Requirements, December 1990, Washington D.C., 1990