1. J. Lafontaine, Integration Functions with Values in a Banach Space (Springer, New York, 2015).
2. A. C. Chiang, Fundamental Methods of Mathematical Economics (Mc Graw Hill, New York, 1984).
3. A. V. Dmitruk, A. A. Milyutin, and N. P. Osmolovskii, UspekhiMat. Nauk 35 (6 (216)), 11 (1980) [Russian Math. Surveys 35 (6), 11 (1980)].
4. É. M. Galeev and V. M. Tikhomirov, Optimization: Theory, Examples, Problems (Editorial URSS, Moscow, 2000) [in Russian].
5. B. H. Pourciau, Amer. Math. Monthly 87 (6), 433 (1980).