Points and triangles in the plane and halving planes in space
B. Aronov, B. Chazelle, H. Edelsbrunner, L. Guibas, M. Sharir, R. Wenger, Discrete &; Computational Geometry 6 (1991) 435–442.

Temporal proof methodologies for real-time systems
T.A. Henzinger, Z. Manna, A. Pnueli, in:, Proceedings of the 18th ACM SIGPLAN-SIGACT Symposium on Principles of Programming Languages, ACM, 1991, pp. 353–366.

The temporal specification and verification of real-time systems 
T.A. Henzinger, The Temporal Specification and Verification of Real-Time Systems , Stanford University, 1991.

Time for logic
R. Alur, T.A. Henzinger, SIGACT News 22 (1991) 6–12.

The benefits of relaxing punctuality
R. Alur, T. Feder, T.A. Henzinger, in:, Proceedings of the 10th Annual ACM Symposium on Principles of Distributed Computing, ACM, 1991, pp. 139–152.