Gaya APA
Johnson, C, C. et al (1988).
SUMATERA GEOCHEMICAL AND MINERAL EXPLORATION PROJECT NSGMEP .
Bandung:
Pusat Sumber Daya Geologi.
Gaya MLA
Johnson, C., C,. et al.
"SUMATERA GEOCHEMICAL AND MINERAL EXPLORATION PROJECT NSGMEP".
Bandung:
Pusat Sumber Daya Geologi,
1988.
Geokimia.