1. Symbolische Maschinen;Krämer,1988
2. Operative schriften als geistestechnik. zur vorgeschichte der informatik;Krämer,1993
3. On computable numbers with an application to the entwcheidungsproblem;Turing,1936-1937
4. “Three models for the description of languages;Chomsky;Inst. Radio Eng.,1956
5. The algebraic theory of context-free languages;Chomsky,1963