Citazione Stile APA (7a Edizione)

Purton, R. W. (1965). Days of challenge (3. impression.). Collins Clear-Type Press.

Citazione stile Chigago Style (17a edizione)

Purton, Rowland W. Days of Challenge. 3. impression. London: Collins Clear-Type Press, 1965.

Citatione MLA (9a ed.)

Purton, Rowland W. Days of Challenge. 3. impression. Collins Clear-Type Press, 1965.