Biswas, S. B., & Biswas, A. (1993). An introduction to viruses (4th rev. ed.). Vikas Publishing House Pvt Ltd.

Biswas, S. B., and Amita Biswas. An Introduction to Viruses. 4th rev. ed. New Delhi: Vikas Publishing House Pvt Ltd, 1993.

Biswas, S. B., and Amita Biswas. An Introduction to Viruses. 4th rev. ed. Vikas Publishing House Pvt Ltd, 1993.