Arnold, Donna M. Serge Jaroff and His Don Cossack Choir: Two Rare Scores at the University of North Texas Music Library, text, 2015; (https://digital.library.unt.edu/ark:/67531/metadc801994/m1/1/: accessed November 21, 2018), University of North Texas Libraries, Digital Library, digital.library.unt.edu; .