Uris, Auren
The efficient executive
McGraw-Hill , 1957
Buku Teks
Becker, Selwyn W. (Selwyn William), 1929-
The efficient organization
Elsevier, 1975
Buku Teks
Efficient reading
Artikel Jurnal
Kennedy, Barry W.
Energy efficient transformers
McGraw-Hill, 1998
Buku Teks
Lloyd, Lewis E.
Techniques for efficient research
Chemical Publishing Company, Inc., 1966
Buku Teks