Galba, E. F., Deineka, V. S., & Sergienko, I. V. (2011). Existence and uniqueness of weighted pseudoinverse matrices and weighted normal pseudosolutions with singular weights.
Ukrains’kyi Matematychnyi Zhurnal,
63(1), 80-101.
https://umj.imath.kiev.ua/index.php/umj/article/view/2700