KUMAR, S. .; SINGH, M. B. Disparities in Agricultural Productivity in Ballia District: A Perception Survey. National Geographical Journal of India , [S. l.], v. 57, n. 3, p. 9–14, 2011. Disponível em: https://ngji.in/index.php/ngji/article/view/531. Acesso em: 29 apr. 2024.