1. On strong product integration;Dollard;J. Functional Analysis,1978
2. Theory of Ordinary Differential Equations;Coddington,1955
3. Operations Infinitesimales Lineaires;Volterra,1938
4. On the operator equation BX − XA = Q;Rosenblum;Duke Math. J.,1956
5. Linear operator equations;Lumer,1959