Cite

Siam 1 inch to 1 mile Bangkok West.

MLA

Centre, Great Britain. Army. Royal Engineers. Survey Production. Siam 1 Inch to 1 Mile Bangkok West. Survey Production Centre, 1945. https://collections.library.yale.edu/catalog/15511932.

APA, 6th edition

Centre, G. B. A. R. E. S. P. (1945). Siam 1 inch to 1 mile Bangkok West. [Topographic maps]. Survey Production Centre, https://collections.library.yale.edu/catalog/15511932.