Norton, Peter
Microsoft Corp., 1985
Buku Teks SO
Norton, Peter
Brady Pub., 1993
Buku Teks SO
Robertson, S. Ian
Psychology Press, 2001
Buku Teks SO
Hodnett, Edward, editor
Harper & Brothers, 1955
Buku Teks SO
Briggs, William
Society for Industrial and Applied Mathematics, 2005
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