N.T.Q. THUAN and D.S. RANA (2001) “Productivity and response of quality brassicas (Brassica sp.) cowpea (Vigna unguiculata) sequence under different sources of nutrients and sulphur levels”, Indian Journal of Agronomy, 55(4), pp. 264–269. doi:10.59797/ija.v55i4.4761.