Cita APA (7a ed.)

Gregory, J. (1915). Geology of today: A popular introduction in simple language. Seeley, Service.

Cita Chicago Style (17a ed.)

Gregory, J.W. Geology of Today: A Popular Introduction in Simple Language. London: Seeley, Service, 1915.

Cita MLA (9a ed.)

Gregory, J.W. Geology of Today: A Popular Introduction in Simple Language. Seeley, Service, 1915.