Mecheri , S., and T. Prasad. “Fuglede – Putnam Type Theorems for Extension of $M$-Hyponormal Operators”. Ukrains’kyi Matematychnyi Zhurnal, Vol. 74, no. 1, Jan. 2022, pp. 89 - 98, doi:10.37863/umzh.v74i1.2355.