Rabanovych, V.I. and Samoilenko, Y.S. (2001) “Scalar Operators Representable as a Sum of Projectors”,
Ukrains’kyi Matematychnyi Zhurnal, 53(7), pp. 939–952. Available at:
https://umj.imath.kiev.ua/index.php/umj/article/view/4315 (Accessed: 10 April 2025).