Tufaila, M., L. O. Safiuddin, R. Eso, S. Kasmiati, H. Syaf, L. O. A. Nur Ramadhan, . Hasrorayan, and . Ardin. “Variation of Chemical Elements and Their Associations in Laterite Soil Profile”. JOURNAL OF TROPICAL SOILS, vol. 20, no. 2, May 2016, pp. 111-8, doi:10.5400/jts.2015.v20i2.111-118.