Valov, Vesko. “Surjective Characterizations of Metrizable $LC^{\infty}$-Spaces”. Ann. Sofia Univ. Fac. Math. and Inf. 85 (December 12, 1993): 43–47. Accessed November 22, 2024. https://annual.uni-sofia.bg/index.php/fmi/article/view/452.