KUMAR, PRAMOD, et al. “Effect of Planting System and Phosphorous on Productivity, Moisture Use Efficiency and Economics of Sole and Intercropped Pigeonpea (Cajanus Cajan) under Rainfed Conditions of Northern India”. The Indian Journal of Agricultural Sciences, vol. 83, no. 5, May 2013, https://epubs.icar.org.in/index.php/IJAgS/article/view/29642.