Separation of the Sturm-Liouville differential operator with an operator potential. - A. S. Mohammed; H. A. Atia (Appl. Math. Comput., 2004)

Separation of the general second order elliptic differential operator with an operator potential in the weighted Hilbert spaces. - A. S. Mohamed; H. A. Atia (Appl. Math. Comput., 2005)