Hidayat, Yayat, Naik Sinukaban, Hidayat Pawitan, and Kukuh Murtilaksono. 2008. “Reformulation of Crop and Management Factor in ANSWERS Model”. JOURNAL OF TROPICAL SOILS 13 (2):155-60. https://doi.org/10.5400/jts.2008.v13i2.155-160.