Gaya APA
Wulfinghoff.Donald.R, . (1999).
Energy Effiency Manual (E-Book) .
United States of America:
Energy Institute Press.
Gaya MLA
Wulfinghoff.Donald.R, .
"Energy Effiency Manual (E-Book)".
United States of America:
Energy Institute Press,
1999.
E-book.