APA (7th ed.) Citation

Immerwahr, G. (1979). How many people in Sri Lanka? Author.

Chicago Style (17th ed.) Citation

Immerwahr, George. How Many People in Sri Lanka? [s.l.]: Author, 1979.

MLA (9th ed.) Citation

Immerwahr, George. How Many People in Sri Lanka? Author, 1979.

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