Approximate solution of operator equations - Krasnoselʹskij, Mark Aleksandrovič 1920-1997; Vainikko, Gennadi 1938-; Zabrejko, Petr Petrovič 1939-; Rutitskij, Jakov Bronislavovič; Stetsenko, V. Ya (Wolters-Noordhoff, 1972)