- "Prolog as the First Programming Language" (PDF) , ACM inroads (SIGCSE Bulletin) V39, N4 (Dec 2007), 61-64; WORLDCOMP'07 talk slides .
- "A Simplified View of Nerode Equivalence" (PDF), Computing Letters Vol. 1, No. 3 (2005), 93-96.
- Specifying and Proving Object-oriented
Programs (PDF), Proc. 2004 Hawaii Inter. Conf. on Computer Sciences, 190-206;

talk slides. - Formal Models of Computation:
the Ultimate Limits of Computing,
World Scientific Pub. Co., 2001, 532 pp.
- "A concise history of the Computer Science Department at the
University of Iowa 1965/1995", IEEE Annals of the History of Computing,
to appear; HTML version.
- "Algebraic specification of objects", Math. Modelling & Sci.
Comput. 6(1996); also presented at the Tenth Inter. Conf. on Mathematical
Modelling and Scientific Computing, Boston MA, 1995.
- "Software development for high performance computing",
presented at
America in the Age of Information: A Forum,
sponsored by the Committee on Information and Communications,
National Science and Technology Council, Bethesda MD, 1995;
electronic dissemination via World Wide Web,
PostScript or
HTML .
[jointly with T. Rus]
- "A case study comparison of four declarative programming languages",
Software - Practice and Experience 20,1(1990), 49-65.
- "Semantic specification using logic programs", Logic Programming: Proc.
North American Conf. 1989(Vol. 2), E. L. Lusk & R. A. Overbeek(eds.), MIT
Press, 1989, 772-794. [jointly with S. Sataluri]
- "Structuring FP-style functional programs", Computer Languages 11,2(1986), 55-63.
- "A proposal for the comparison of types in Pascal and associated semantic
models", Computer Languages 9,2(1984), 71-87.
- "Formal semantics and abstract properties of string pattern operations
and extended formal language description mechanisms", SIAM Jour. on
Computing 12,1(1983), 166-188. [jointly with R. Limaye]
- "Verifying abstract data types with SNOBOL4", Software - Practice and
Experience 12(1982), 627-640.
- "A note on Pascal scopes" (PDF),
Pascal News 17(1980), 62. [jointly
with T. Baker]
- "Does block=scope in Pascal?" (PDF),
Pascal News 17(1980), 60-61. [jointly
with T. Baker]
- "String pattern matching in polynomial time", Proc. 6th Ann. ACM
Symp. on Principles of Programming Languages, 1979, 222-225. [jointly
with K. Liu]
- "On the realization of data graphs", Proc. Inter. Computer Symp.,
Taipei, Taiwan, 1978, 11 pp. [jointly with K. Liu]
- "Formal models for string patterns", in Current Trends in Programming
Methodology Vol. IV: Data Structuring (R. Yeh, ed.), Prentice-Hall, 1978,
216-240.
- "Recent developments in the theory of data structures", Computer
Languages 3 (1978), 37-52; also invited talk at 4th Texas Conf. on
Computing Systems, 1975.
- "On the impossibility of content exchange through the by-name
parameter transmission mechanism", SIGPLAN Notices 11,11(1976), 38-41.
- "An analysis of grammars by their derivation sets", Information and
Control 24 (1974), 389-398.
- "Data stucture analysis using formal languages", Proc. Computer Science
Conf. (abstracts)/SIGCSE, Neil House, Columbus, Ohio, Feb. 1973, p.51 (W3B7).
- "S-semigroups of automata", Jour. ACM 19(1972), 3-10. [jointly with S.
Hedetniemi and R. Oehmke]
- "On the combinatorial complexity of context-free grammars", Information
Processing 71(1972), North-Holland Pub., 59-60; also presented at IFIP 71,
Ljubljana, Yugoslavia.
- "Towards a theory of data structures", Jour. Computer and System
Science 5(1971), 475-488.
- "Formal languages and data structures", presented at Third Hawaii Inter.
Conf. on System Science, 1970.
- "On the strong connectedness of the direct product", IEEE Trans.
Electronic Computers EC-16(1967), 90.
- "On the automorphism group of an automaton", Jour. ACM 12(1965), 566-569.
- "Algebraic structure of automata"
(PDF), Ph.D. thesis, Michigan State University Library, 108 286 THS, 1964.
- "Isomorphism groups of automata", Jour. ACM 9(1962), 469-476.
- "Structure preserving properties of certain classes of functions on automata"(PDF), Tech. Bull. 16, Computer Laboratory, Michigan State Univ., May 1961, 28 pp; also Notices of the Amer. Math. Society 8(1961), 582-17, and presented at 1961 summer meeting of Amer. Math. Society in Stillwater OK.