APA
Verma P. S, . (1971). A Manual of Practical zoology : Invertebrates. S. chand & company ltd, New Delhi: .
Chicago
Verma P. S, . 1971. A Manual of Practical zoology : Invertebrates. S. chand & company ltd, New Delhi: .
Harvard
Verma P. S, . (1971). A Manual of Practical zoology : Invertebrates. S. chand & company ltd, New Delhi: .
MLA
Verma P. S, . A Manual of Practical zoology : Invertebrates. S. chand & company ltd, New Delhi: . 1971.