APA (7th ed.) Citation

Squirrell, H. C., Downing, R. A., & Kelk, B. (1969). Geology of the South Wales coalfield (3d ed.). H. M. Stationery Off..

Chicago Style (17th ed.) Citation

Squirrell, H. C., Richard A. Downing, and B. Kelk. Geology of the South Wales Coalfield. 3d ed. London: H. M. Stationery Off., 1969.

MLA (8th ed.) Citation

Squirrell, H. C., et al. Geology of the South Wales Coalfield. 3d ed. H. M. Stationery Off., 1969.