“…For a systematic account of the development in the theory of the matrix differential Riccati equation up to seventies see, for example, the survey [1]. More recently there appeared papers where this equation was considered as a Bäcklund-type transformation for some integrable systems of differential geometry, in particular, for the Lamé and the Bourlet equations, and a relevant superposition principle for the equation has been studied on the basis of the theory of Lie algebras, see, for example, [2] and references therein. The matrix Riccati equation also arises as equation of motion on Grassmann manifolds and on homogeneous spaces attached to the Hartree-Fock-Bogoliubov problem, see, for example, [3] and references therein; and in some other subjects of applied mathematics and physics such as optimal control theory, plasma, etc., see, for example, [4].…”