Who was born in an earlier year, Ivan Fesenko or Alexander Gelfond
Ivan Fesenko Ivan Fesenko (Russian: Иван Борисович Фесенко ; born 1962) is a mathematician working in number theory and other areas of modern mathematics.
Ivan Feodosiyovych Korsak Ivan Korsak (Ukrainian: Iва́н Феодо́сійович Ко́рсак ; born September 15, 1946) is a Ukrainian writer and journalist.