John, Bierhorst (2016), Duggan, Anne E.; Haase, Donald; Callow, Helen J. (eds.), "Bear's Son", Folktales and Fairy Tales: Traditions and Texts from around the World, vol. 1 (2 ed.), ABC-CLIO, p. 105, ISBN9780313334429
Puhvel (2010), p. 4, note 9: "While more recent folklorists prefer to call this folktale 'The Three Stolen Princesses', classified by Aarne as Type 301, it would seem more appropriate in a consideration involving analogy and parallelism with Beowulf to use the name 'The Bear's Son', employed by Panzer and other[s]. Puhvel, Martin (2010), Beowulf and the Celtic Tradition, Wilfrid Laurier Univ. Press, ISBN9781554587698
Thompson, Stith (1919), "John the Bear", European Tales Among the North American Indians: A Study in the Migration of Folk-tales, Language Series, Vol. II, No. 34, Board of Trustees of Colorado College, pp. 334–345
Barakat (1967), pp. 5–6, with "iron weapon"; p. 8, with machete. Barakat, Robert A. (January 1967). "John of the Bear and 'Beowulf'". Western Folklore. 26 (1): 1. doi:10.2307/1498482. JSTOR1498482.
Barakat, Robert A. (1965). "The Bear's Son Tale in Northern Mexico". The Journal of American Folklore. LXXVIII (310): 330. JSTOR538440:
"European variants hero a magic sword or walking stick; Mexican versions give him a machete", Barakat (1965), p. 330
Barakat (1967), pp. 5–6, with "iron weapon"; p. 8, with machete. Barakat, Robert A. (January 1967). "John of the Bear and 'Beowulf'". Western Folklore. 26 (1): 1. doi:10.2307/1498482. JSTOR1498482.
Boas, Franz (1912), "Comparative notes on New-Mexican and Mexican Spanish Folk-tales", Journal of American Folklore, 25: 254–258, JSTOR534821 (cited by Espinosa (1014))