Sugiyanta, S., Tustiyani, I. and Dinarti, D. (2019) “Improving the Effectivity of Urea Fertilizer in Shallot by Using Urease and Nitrification Inhibitors”, Jurnal Ilmu Pertanian Indonesia, 24(4), pp. 289-294. doi: 10.18343/jipi.24.4.289.