44 John C. Ewers, The Horse in Blackfoot Indian Culture, Bureau of American Ethnology Bulletin 159 (Washington: Smithsonian Institution, 1955), pp. 2-19, traces the introduction of the horse to the northern plains.
44 John C. Ewers, The Horse in Blackfoot Indian Culture, Washington, Smithsonian Institution, 1955, Bureau of American Ethnology Bulletin 159, pp. 2 à 19, retrace l'apparition du cheval dans les plaines du Nord.