Narayan, K.P., Verma, S.K., Kant, S., Kushwaha, R.A.S., Kumar, S., Garg, R., Srivastava, A., Bajaj, D.K. and Sonkar, S. 2019. Predictors of co-morbidities in chronic obstructive pulmonary disease patients at a tertiary care centre in north India. International Journal of Research in Medical Sciences. 7, 11 (Oct. 2019), 4154–4160. DOI:https://doi.org/10.18203/2320-6012.ijrms20194984.