Victor R. Basili and Albert J. Turner "A hierarchical machine model for the semantics of programming languages" pp152-164

[HLLCA 1973] (1973) SIGPLAN Notices 8(11) November 1973 Proceedings of the ACM-IEEE symposium on High-level-language computer architecture 1973, College Park, Maryland, United States  

Languages mentioned HGL {1970} Hierarchical graph language