Mujiyo, M., S. Sutarno, S. Suwarto, R. Budiono, and novi rahmawati sutopo. “Inhibiting Factors of Land Suitability for Piper Nigrum L. in a Hilly Area of Tirtomoyo District, Central Java”. JOURNAL OF TROPICAL SOILS, vol. 25, no. 1, Jan. 2020, pp. 29-37, doi:10.5400/jts.2020.v25i1.29-37.