Yuliani, S.S., Useng, D. and Achmad, M. 2017. Analisis Kandungan Nitrogen Tanah Sawah Menggunakan Spektrometer. Jurnal Agritechno. 10, 2 (Oct. 2017), 188–202. DOI:https://doi.org/10.20956/at.v10i2.71.