Savkin, V.I. (1994) “A criterion for Banach manifolds with a separable model to be finite-dimensional”,
Ukrains’kyi Matematychnyi Zhurnal, 46(8), pp. 1099–1103. Available at:
https://umj.imath.kiev.ua/index.php/umj/article/view/5666 (Accessed: 7 April 2025).