K. R. Kumar, V. S. Vani, K. U. Jyothi, and K. Sasikala, “Effect of plant densities and phosphorus levels on the growth and yield of vegetable cowpea (Vigna unguiculata (L.) walp)”, VegSci, vol. 39, no. 01, pp. 59–62, Jun. 2012, doi: 10.61180/.