Gilbert, Julie (1995). Opposite Attraction – The Lives of Erich Maria Remarque and Paulette Goddard.Pantheon Books; ISBN0-679-41535-1, pp. 37–41 for parents' names and backgrounds, as well as Alta's birth year; pp. 159–60 for Levy's death year and p. 477 for Alta's death year.
1-55783-551-9
Monush, Barry (2003). Monush, Barry (ed.). Screen World Presents the Encyclopedia of Hollywood Film Actors: From the Silent Era to 1965, Volume 1. 1. Hal Leonard Corporation. p. 282. ISBN1-55783-551-9[მკვდარი ბმული].
978-0-252-09369-2
Rimler, Walter (2009). George Gershwin: An Intimate Portrait. University of Illinois Press. p. 147. ISBN978-0-252-09369-2[მკვდარი ბმული].
