Cita APA (7th ed.)
Johnstone, P. (1978). Operation world: A day-to-day guide to praying for the world (4th ed.). STL.
Cita Chicago (17th ed.)
Johnstone, Patrick. Operation World: A Day-to-day Guide to Praying for the World. 4th ed. Kent, England: STL, 1978.
Cita MLA (9th ed.)
Johnstone, Patrick. Operation World: A Day-to-day Guide to Praying for the World. 4th ed. STL, 1978.
Atenció: Aquestes cites poden no estar 100% correctes.