S. Afina Aliyan, A. S. Bahri, A. Widodo, and W. Utama, “Remote Sensing Data Integration of Landsat 8 and SRTM for Geomorphological Characteristics Identification in Karst Pringkuku, Pacitan, East Java”, Int. J. Adv. Sci. Eng. Inf. Technol., vol. 10, no. 1, pp. 212–218, Feb. 2020.