E. M. Landis

• Second order equations of elliptic and parabolic type
• Uravnenii͡a︡ vtorogo pori͡a︡dka ėllipticheskogo i parabolicheskogo tipov
• Uravnenii͡a︡ vtorogo proi͡a︡dka ėllipticheskogo i parabolicheskogo tipov