Comer, M. J.
Tata McGraw-Hill, 1979
Buku Teks
Trenaman, J.M.
Longmans , 1967
Buku Teks
Field Enterprises Educational Corporation, 1963
Buku Referensi
Smart, W.M.
Cambridge University, 1962
Buku Teks
Field Enterprises Educational Corporation, 1963
Buku Referensi