Mortimer J. Adler, editor in chief
Encyclopedia Britanica, 1994
Buku Referensi
Holt, Rinehart and Winston, 1961
Buku Teks
Artikel Jurnal
edited by Harold C. Gardiner
Devin-Adair Co., 1949
Buku Teks
Shaffira Diraprana Gayatri
2014
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