APA (7th ed.) Citation

Armstrong, A. K. (1955). Preliminary observations on the Mississippian system of northern New Mexico. [publisher not identified].

Chicago Style (17th ed.) Citation

Armstrong, Augustus K. Preliminary Observations on the Mississippian System of Northern New Mexico. Socorro: [publisher not identified], 1955.

MLA (9th ed.) Citation

Armstrong, Augustus K. Preliminary Observations on the Mississippian System of Northern New Mexico. [publisher not identified], 1955.