Boyd, William C., author
Abelard-Schuman, 1955
Buku Teks
Count, Earl Wendel
Henry Schuman, 1950
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Seda, Francisia Saveria Sika Ery, author
1992
Artikel Jurnal
Smallman, R.E., author
Erlangga, 1999
Buku Teks
Seligman, C.G., author
Thornton Butterworth, 1939
Buku Teks