Nybakken, James W. (James Willard), author
Harper Collins, 1993
Buku Teks
Ford, E. David, author
Cambridge University Press, 2000
eBooks
Jarvis, Peter J., author
Prentice-Hall, 2000
Buku Teks
edited by S.E. Jorgensen, B. Halling-Sorensen, S.N. Nielsen
Lewis Publishers, 1996
Buku Referensi
Shmelev, Stanislav E., author
[Springer, Springer], 2012
eBooks