The secret of the ages.

MLA

Collier, Robert. The Secret of the Ages. 27th edition Ramsey: Collier, 1975.

APA

Collier, R. (1975). The secret of the ages. 27th edition Ramsey: Collier.

Chicago

Collier, Robert, The Secret of the Ages. 27th edition Ramsey: Collier, 1975.