Entered from booking ledger and New York Times concert listing and review. "Who Makes Music and Where." New York Times (1923-), May 5 1968, p. D16. ProQuest. Web. 19 Dec. 2024. Sherman, Robert. "Van Putten, Baritone, Sings at Carnegie Recital Hall." New York Times (1923-), May 06 1968, p. 58. ProQuest. Web. 19 Dec. 2024.