Shepherd, W., & Shepherd, D. W. (2003). Energy studies (2nd ed.). Singapore: Imperial College Press.
Παραπομπή Chicago StyleShepherd, W., and D. W. Shepherd. Energy Studies. 2nd ed. Singapore: Imperial College Press, 2003.
Παραπομπή MLAShepherd, W., and D. W. Shepherd. Energy Studies. 2nd ed. Singapore: Imperial College Press, 2003.
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