APA (7th ed.) Citation

Nalwalk, A. J. (1967). Geology of the North Wall of the Puerto Rico Trench. [publisher not identified].

Chicago Style (17th ed.) Citation

Nalwalk, Andrew Jerome. Geology of the North Wall of the Puerto Rico Trench. [Place of publication not identified]: [publisher not identified], 1967.

MLA (9th ed.) Citation

Nalwalk, Andrew Jerome. Geology of the North Wall of the Puerto Rico Trench. [publisher not identified], 1967.