Middleton, Robert Gordon, 1908-
Audels handybook of practical electricity
Bombay: D.B. Taraporevala Sons, 1969
 Buku Teks
Anderson, Edwin P.
Audels radiomans guide
D.B. Taraporevala Sons, 1965
 Buku Referensi
Dunn, John A., 1949-
Modern Russian Grammar : a practical guide
Routledge, 2009
 Buku Teks
Dunn, John, 1940-
Modern Russian grammar : a practical guide
Routledge, 2009
 Buku Referensi
Frank, Marcella
Modern english : a practical reference guide
Prentice-Hall, 1972
 Buku Teks SO