Hutton, Wendy
Periplus, 1997
Buku Referensi
Allen, Gerald R., author
Periplus, 1997
Buku Referensi
Strange, Morten
Periplus Editions, 1998
Buku Referensi
Sharp, Ilsa, author
Oxford University Press, 1997
Buku Referensi
National Academy of Science, 1975
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