APA
Ocallaghah Paul, . (1992). Energy management. : London mcgrew hill.
Chicago
Ocallaghah Paul, . 1992. Energy management. : London mcgrew hill.
Harvard
Ocallaghah Paul, . (1992). Energy management. : London mcgrew hill.
MLA
Ocallaghah Paul, . Energy management. : London mcgrew hill. 1992.