Gaya APA

a.l., R, A, P, D, E. (1981). The East Kalimantan Coal Project Report On The Coal Geology Of South Prangat Area Kutai Basin, East Kalimantan . Bandung: Pusat Sumber Daya Geologi.

Gaya MLA

a.l., R., Addison,, Ph, D, Et. "The East Kalimantan Coal Project Report On The Coal Geology Of South Prangat Area Kutai Basin, East Kalimantan". Bandung: Pusat Sumber Daya Geologi, 1981. Batubara.