Gaya APA

Clarke, M. (1982). Geologi lembar Pematangsiantar, Sumatra = The geology of the Pematangsiantar Quadrangle, Sumatra . Bandung: Geological Research and Development Center.

Gaya MLA

Clarke, M.C.G.. "Geologi lembar Pematangsiantar, Sumatra = The geology of the Pematangsiantar Quadrangle, Sumatra". Bandung: Geological Research and Development Center, 1982. Text.