1.
Grechneva MA, Stegantseva PG. On the existence of a surface in the pseudo-Euclidean space with given Grassman image. Ukr. Mat. Zhurn. [Internet]. 2016Oct.25 [cited 2020Dec.5];68(10):1320=1329. Available from: http://umj.imath.kiev.ua/index.php/umj/article/view/1923