Gaya APA
Johnstone, P. (1978).
Operation World: A Day to Day Guide to Praying for the World, 4th Edition (4th Ed.).
England:
WEC Publications.
Gaya MLA
Johnstone, Patrick.
"Operation World: A Day to Day Guide to Praying for the World, 4th Edition".
4th Ed.
England:
WEC Publications,
1978.
Text.