Claxton, john, author
Glorier International, 1999
Buku Referensi
Fraser, Jill Andresky, author
Bloomberg Press, 2002
Buku Teks
Artikel Jurnal
Tobin, Daniel R., 1946-, author
McGraw-Hill, 2012
Buku Teks
Kallestad, Walt
Michigan Zonder Van 1998,
Buku Teks