. M. . Mawardi, P. H. T. . Nugraheni, L. . Sutiarso, S. . Virgawati, and M. . Fuadi, “Mapping the Variable-Rate Application (VRA) of Precision Fertilizing for Soybean”, J. Adv. Res. Appl. Mech. , vol. 51, no. 1, pp. 1–9, Nov. 2020.