- Arteaga, Carlos Centralizers of immersions of the circle. Proc. Amer. Math. Soc. 109 (1990), no. 3, 849--853.
- de Avellar, C. E.; Marconato, S. A. S. Difference equations with delays depending on time. Bol. Soc. Brasil. Mat. (N.S.) 21 (1990), no. 1, 51--58.
- de Oliveira, César R. On the complete system of observables in quantum mechanics. J. Math. Phys. 31 (1990), no. 10, 2406--2409.
- Izé, A. F. Lyapunov numbers for a countable system of ordinary differential equations. Ann. Polon. Math. 51 (1990), 167--178.
- Izé, A. F. An infinite-dimensional extension of theorems of Hartman and Wintner on monotone positive solutions of ordinary differential equations. Proc. Amer. Math. Soc. 110 (1990), no. 1, 77--84.
- Fernandez Long de Foglio, Susana New and old results concerning Henstock's integrals. New integrals (Coleraine, 1988), 25--37, Lecture Notes in Math., 1419, Springer, Berlin, 1990.