APA (7th ed.) Citation

Sommerfield, J. Volunteer in Spain / John Sommerfield. New York : Alfred a Knopf, 1937. New York : Vail-Ballou.

Chicago Style (17th ed.) Citation

Sommerfield, John. Volunteer in Spain / John Sommerfield. New York : Alfred a Knopf, 1937. New York : Vail-Ballou.

MLA (8th ed.) Citation

Sommerfield, John. Volunteer in Spain / John Sommerfield. New York : Alfred a Knopf, 1937. New York : Vail-Ballou.

Warning: These citations may not always be 100% accurate.