Sulistyo, Bambang, et al. “PROPOSED MODEL ON LEVELS OF DEGRADED LAND AT MERAWU WATERSHED, BANJARNEGARA REGENCY, CENTRAL JAVA PROVINCE, INDONESIA”. BIOTROPIA, vol. 24, no. 3, Dec. 2017, pp. 220-9, doi:10.11598/btb.2017.24.3.730.