GalbaE. F., DeinekaV. S., and SergienkoI. V. “Expansion of Weighted Pseudoinverse Matrices in Matrix Power Products”. Ukrains’kyi Matematychnyi Zhurnal, Vol. 56, no. 11, Nov. 2004, pp. 1539-56, https://umj.imath.kiev.ua/index.php/umj/article/view/3864.