Also in 1940 he published a paper written jointly with Erdos, Kac and Wintner: Ramanujan sums and almost periodic functions.
Din sa 1940 siya nai-publish ng isang papel na may nakasulat na sama-sama Erdos, Kac at Wintner: Ramanujan sums at halos pana-panahon na pag-andar.