Edwin Kimutai Kanda, Aidan Senzanje, and Tafadzwanashe Mabhaudhi, “Effect of Moistube and subsurface drip irrigation on cowpea (Vigna unguiculata (l.) Walp) production in South Africa”, WSA, vol. 46, no. 2 April, Apr. 2020, doi: 10.17159/wsa/2020.v46.i2.8234.