DorogovtsevA.A., KopytkoB., KorolyukV.S., MitropolskiyY.A., SamoilenkoA.M., SytayaG.N. and SkorokhodA.V. 2002. Mykola Ivanovych Portenko (On His 60th Birthday). Ukrains’kyi Matematychnyi Zhurnal. 54, 2 (Feb. 2002), 147-148.