McColley, Kevin
Praying to a laughing god : a novel / Kevin McColley
Simon & Schuster , 1998
Buku Teks
Turner, Jonathan H.
Herbert Spencer: a renewed appreciation
Sage Publications, 1989
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Spencer, Herbert
First principles / Herbert Spencer
Watts, 1937
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Sieff, Marcus
Manajemen gaya Marks & Spencer
Mitra Utama, 1994
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Spencer, Lyle M.
Competence at work/ Lyle M. Spencer, Signe M. Spencer
John Wiley & Sons, 1993
Buku Teks