Gill, Paul, author
CRC Press, Taylor & Francis Group, 2009
Buku Teks
Hubert, Charles I. (Charles Irving), author
McGraw-Hill, 1969
Buku Teks
Soni, M.L.
Delhi: Shamput Rai and Sons, 1977
Buku Teks
Starr, A.T.
Sir Isaac Pitman & Sons, 1965
Buku Teks
Guile, A.E., author
Pergamon Press, 1982
Buku Teks