Raghunathan K, Layton JB, Ohnuma T, Shaw AD. Observational research using propensity scores. Adv Chronic Kidney Dis. 2016 Nov;23(6):367-72. doi: 10.1053/j.ackd.2016.11.010
Capdevila Bert R, Marsal Mora JR, Pujol Salud J, Anguera Farran R. Prevalence study of iodine deficiency in a 6-year-old school population. An Pediatr (Barc). 2010 May;72(5):331-8. doi: 10.1016/j.anpedi.2009.12.023
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