Lebon, J. H. G., author
Hutchinson University Library, 1969
Buku Teks
Huntington, Ellsworth, author
John Wiley & Sons, 1951
Buku Teks
Huntington, Ellsworth, author
John Wiley & Sons, 1960
Buku Teks
Kuby, Michael, author
Wiley, 2013
Buku Teks
Goodall, Brian, author
Penguin Books, 1987
Buku Referensi