11. Three Gothic Ballads Collection: Concert Programs (SOM) Contributers: Duke, John (composer), Warren Hettinga (baritone), and Ann Nadeau (piano) Performance: Graduate Voice Recital (DMA) Performance Date: 1975-02-23 Location: Music and Performing Arts Library, University of Illinois Concert Program: v.24 p.107
12. Verzagen Collection: Concert Programs (SOM) Contributers: Brahms, Johannes (composer), Warren Hettinga (baritone), and Ann Nadeau (piano) Performance: Graduate Voice Recital (DMA) Performance Date: 1975-02-23 Location: Music and Performing Arts Library, University of Illinois Concert Program: v.24 p.107