Yusenko, K.A. (2006) “On quadruples of projectors connected by a linear relation”,
Ukrains’kyi Matematychnyi Zhurnal
, 58(9), pp. 1289–1295. Available at:
https://umj.imath.kiev.ua/index.php/umj/article/view/3531
(Accessed: 10 April 2025).