Phanikumar CV, Maitra B. Valuing urban bus attributes: an experience in Kolkata. J Public Transport. 2006;9(2):69-87. doi: 10.5038/2375-0901.9.2.4
Phani Kumar CV, Basu D, Maitra B. Modeling generalized cost of travel for rural bus users: a case study. J Public Transport. 2004;7(2):59-72. doi: 10.5038/2375-0901.7.2.4
Allan JS, Kanda P, Kennedy RC, Cobb EK, Anthony MS, Eichberg JW. Isolation and characterization of simian immunodeficiency virus from two subspecies of African green monkeys. Aids Res Hum Retrovir. 1990 Mar;6(3):275-85.