Steeds, W.
Longman, 1964
Buku Teks
Singh, Surendra, author
Vikas, 1979
Buku Teks
Van Vlack, Lawrence H., author
Addison-Wesley, 1982
Buku Teks
Timings, R.L. (Roger Leslie), 1927-, author
Longman Scientific, 1989
Buku Teks
Timings, R.L. (Roger Leslie), 1927-, author
Longman, 1991
Buku Teks