. . . "Entered from booking ledger and New York Times review.\r\n\"2 Singers Give Recital.\" New York Times (1923-Current file), Apr 20 1956, p. 21. ProQuest. Web. 10 Mar. 2021." . . . . . "joint recital" . . "1956-04-19T20:30:00"^^ . "Olga Maikapar, Mezzo-Soprano, and Vladimir Derwies, Tenor" . .