Coercive estimates for a degenerate elliptic system of equations with spectral applications. - Kordan Ospanov (Appl. Math. Lett., 2011)

Solvability of a class of mixed type second order equations and nonlocal estimates. - Mussakan Muratbekov; Kordan Ospanov; Sabit Igissinov (Appl. Math. Lett., 2012)