APA (7th ed.) Citation

Austin, M., Marks, S., & Marks, L. (1963). One hundred miles on horseback. Dawson's Book Shop.

Chicago Style (17th ed.) Citation

Austin, Mary, Saul Marks, and Lillian Marks. One Hundred Miles on Horseback. Los Angeles: Dawson's Book Shop, 1963.

MLA (9th ed.) Citation

Austin, Mary, et al. One Hundred Miles on Horseback. Dawson's Book Shop, 1963.