Gaya APA
Ruswandi, E., Peart, R, J. (1987).
Geophysical Exploration For Primary Tin And Tungsten Mineralisation At Hatapang, Sumatra Utara, Nortern Sumatra .
Bandung:
Pusat Sumber Daya Geologi.
Gaya MLA
Ruswandi, E.., Peart, R., J..
"Geophysical Exploration For Primary Tin And Tungsten Mineralisation At Hatapang, Sumatra Utara, Nortern Sumatra".
Bandung:
Pusat Sumber Daya Geologi,
1987.
Geokimia.