APA (7th ed.) Citation

Siringo, C. A. (1920). History of "Billy the Kid.". [publisher not identified].

Chicago Style (17th ed.) Citation

Siringo, Charles A. History of "Billy the Kid.". [Sante Fe, N.M.]: [publisher not identified], 1920.

MLA (8th ed.) Citation

Siringo, Charles A. History of "Billy the Kid.". [publisher not identified], 1920.