Smith, Dave (2012). Disney Trivia from the Vault: Secrets Revealed and Questions Answered. New York City: Disney Editions. ISBN9781423178576. «Q: Who are Huey, Dewey, and Louie’s parents? Do they appear in any of the cartoons? Sarina, Montreal, Quebec, Canada. A: According to the cartoon Donald’s Nephews, Donald receives a postcard from his sister, Dumbella, saying she is sending the three for a visit. That is the only time we ever hear of Dumbella, and a father’s name is never mentioned.»
