Kotpal, R. L. (1999). The Birds: A Text Book for University Students (4th ed.). Rastogi Publications.
Citazione stile Chigago Style (17a edizione)Kotpal, R. L. The Birds: A Text Book for University Students. 4th ed. Meerut, India: Rastogi Publications, 1999.
Citatione MLA (9a ed.)Kotpal, R. L. The Birds: A Text Book for University Students. 4th ed. Rastogi Publications, 1999.
Attenzione: Queste citazioni potrebbero non essere precise al 100%.