Fakhruddin, Rakhmat. “Biostratigraphy and Depositional Environment of Early to Middle Miocene Sediments at Kulon Progo, Wonosari, and Punung Areas Based on Their Foraminiferal and Palynological Assemblages”. Indonesian Journal on Geoscience, vol. 6, no. 1, Apr. 2019, pp. 73-101, doi:10.17014/ijog.6.1.73-101.