Entered from program calendar and New York Times concert listing and review. "Concert and Opera Programs of the Week." New York Times (1923-Current file): 1. Apr 13 1952. ProQuest. Web. 4 Mar. 2014. "Lange, Soprano, in Recital." New York Times (1923-Current file): 21. Apr 18 1952. ProQuest. Web. 4 Mar. 2014.