| 1970 | ||
|---|---|---|
| 4 | Dennis F. Cudia: The Degree Hierarchy of Undecidable Problems of Formal Grammars STOC 1970: 10-21 | |
| 3 | Dennis F. Cudia: General Problems of Formal Grammars. J. ACM 17(1): 31-43 (1970) | |
| 1968 | ||
| 2 | Dennis F. Cudia, Wilson E. Singletary: Degrees of Unsolvability in Formal Grammars. J. ACM 15(4): 680-692 (1968) | |
| 1 | Dennis F. Cudia, Wilson E. Singletary: The Post Correspondence Problem. J. Symb. Log. 33(3): 418-430 (1968) | |
| 1 | Wilson E. Singletary | [1] [2] |