A nationally representative case-control study of smoking and death in India. by Jha, P, Jacob, B, Gajalakshmi, V, Gupta, P, Dhingra, N, Kumar, R, Sinha, D, Dikshit, R, Parida, D, Kamadod, R, Boreham, J, Peto, R, RGI-CGHR Investigators