APA (7th ed.) Citation

United States. Bureau of Mines. (1931). Index to geophysical abstracts No. 1 to No. 20. [publisher not identified].

Chicago Style (17th ed.) Citation

United States. Bureau of Mines. Index to Geophysical Abstracts No. 1 to No. 20. [Washington]: [publisher not identified], 1931.

MLA (9th ed.) Citation

United States. Bureau of Mines. Index to Geophysical Abstracts No. 1 to No. 20. [publisher not identified], 1931.

Warning: These citations may not always be 100% accurate.