Adji, T. N. “Baseflow Separation of the Bribin River Upstream in Gilap Cave Flowage, Sewu Mountain Karst, Gunung Kidul, Yogyakarta”. Indonesian Journal on Geoscience, vol. 6, no. 3, Sept. 2011, pp. 165-7, doi:10.17014/ijog.6.3.165-175.