Coulton, G.G. (George Gordon), author
Macmillan; University Press, 1938
Buku Teks
Pring, Martin J., author
McGraw-Hill, 1981
Buku Teks
Sunario Waluyo, author
Pusat pengembangan agribisnis, 1979
Buku Teks
Gosden, Chris, author
Cambridge University Press, 2006
Buku Teks
Kern, Hermann
Prestel, 2000
Buku Teks