N. Watanabe and D. Kadir. Geology and Stratigraphy of the Sambungmacan Area. Quaternary Geology of the Hominid Fossil Bearing Formations in Java: Report of the {Indonesia-Japan} Joint Research Project {CTA-41}, 1976-1979, Republic of Indonesia, Ministry of Mines and Energy, Directorate General of Geology and Mineral Resources, Geological Research and Development Centre, volume 4, pages 45-47, 1985.

N. Watanabe and D. Kadir. A Consideration of the Stratigraphic Horizons of Hominid Finds from Sangiran by the Fluorine Method. Quaternary Geology of the Hominid Fossil Bearing Formations in Java: Report of the {Indonesia-Japan} Joint Research Project {CTA-41}, 1976-1979, Republic of Indonesia, Ministry of Mines and Energy, Directorate General of Geology and Mineral Resources, Geological Research and Development Centre, volume 4, pages 359-366, 1985.

N. Watanabe. Early Pleistocene in view of anthropology with special reference to nipponanthropus. Quat. Res., Japan Association for Quaternary Research, volume 9, issue 34, pages 176-183, 1970.