1. G. ADOMIAN: Theory of random systems: Trans. 4th Prague Conf. Information Theory, Statistics, Decision Functions and Random Processes, (1965), 205–222.
2. F.E. BROWDER: Nonlinear monotone operators and convex sets in Banach spaces: Bull. Amer. Math. Soc., 71 (1965), 780–785.
3. M.C. JOSHI AND R.K. BOSE: Some topics in Nonlinear Functional Analysis: Wiley Eastern Ltd., New Delhi (1984).
4. E. KREYSZIG: Introductory functional analysis with applications: John Wiley and Sons, New York (1978).
5. K. KURATOWSKII AND C. RYLL-NARDZEWSKI: A general theorem on selectors: Bull. Acad. Polons. Sci. Ser. Math. Sci. Astr. Phys. 13 (1965), 397–403.