Gaya APA

Muffler, L, R, A, L. (1981). Geothermal Systems: Principles and Case Histories . Chichester: John Wiley & Sons.

Gaya MLA

Muffler, L., Rybach, And, L.J.P.. "Geothermal Systems: Principles and Case Histories". Chichester: John Wiley & Sons, 1981. Text.