Gaya APA

Djunuddin, A. et al (1984). 1985 Index of Northern Sumatra Geological and Chemical Maps, and Northern Sumatra Bibliography . Bandung: Pusat Sumber Daya Geologi.

Gaya MLA

Djunuddin, A.. et al. "1985 Index of Northern Sumatra Geological and Chemical Maps, and Northern Sumatra Bibliography". Bandung: Pusat Sumber Daya Geologi, 1984. Geokimia.