Entered from booking ledger and New York Times concert listing and review. "PROGRAMS OF THE WEEK." New York Times (1923-Current file), May 26 1957, p. 1. ProQuest. Web. 25 Aug. 2021. "DE PAUL, BARITONE, SINGS: ARTIST IS HEARD IN PROGRAM AT CARNEGIE RECITAL HALL." New York Times (1923-Current file), May 27 1957, p. 26. ProQuest. Web. 25 Aug. 2021.