1. Research Notes in Mathematics;Barbu V.,1984
2. Positive definite functions of infinitely many variables in a layer
3. El-Zahaby, S. A. 1990. Optimal Control of a system Governed by parabolic Variational Inequality with an infinite number of variables. UAB International Conference on Differential Equations and Mathematical Physics. March15–211990. presented at the
4. Lecture Notes in Mathematics;Gali I. M.,1984