1. Hähnle R. (2006). Many-Valued Logic, Par-tiality, and Abstraction in Formal Specifica-tion Languages. In Logic Journal of the IGPL. N.13 (4). P. 415–433.
2. Reasoning about partial func-tions in the formal development of programs.;Jones,2006
3. Avoiding the undefined by underspecification;Gries;In Springer Berlin Heidelberg,1995
4. Nikitchenko N. (1998). A composition-nominative approach to program semantics. – Technical report IT-TR: 1998-020. Technical University of Denmark. 103 p.
5. Composition-nominative aspects of address programming.;Nikitchenko;Cybern Syst Anal,2009