1. Syntactic Structures, 2nd Printing, 's-Gravenhage: Mouton and Co., 1962;
2. Indexing and dependency logic for answering english questions
3. A Conceptual Dependency Representation for a Computer-Oriented Semantics, Stanford Univ., Calif., Dept. of Computer Science, CS 130, March, 1969, NTIC No. PB 183903, 209 pages.
4. Automated Language Processing in Annual Review of Information Science and Technology, Ed., Vol 1, 1966, Interscience, New York: pages 137–169.
5. and , Automated Language Processing, in Annual Review of Information Science and Technology, Ed., Vol. 2, 1967, Interscience, New York, pages 161–186.