Gaya APA

Katili, J. (1977). Proceedings of The Second Symposium Integrated Geological Survey of Northern Sumatra (Desember 1977). Bandung: Direktorat Jenderal Pertambangan Umum.

Gaya MLA

Katili, J.A.. "Proceedings of The Second Symposium Integrated Geological Survey of Northern Sumatra". Desember 1977 Bandung: Direktorat Jenderal Pertambangan Umum, 1977. Text.