1. Abstract families of languages;Ginsburg;Amer. Math. Soc. Memoir Number,1969
2. Two-Way Balloon Automata and AFL;Ginsburg;System Development Corporation Report, TM-738/042/00, Santa Monica, California,1968
3. Control sets on grammars;Ginsburg;Mathematical Systems Theory,1968
4. Structure of undecidable problems in automata theory;Hartmanis,1968
5. An approach to a unified theory of automata;Hopcroft;Bell Syst. Tech. J.,1967