Thirlwall, Anthony Philip
English Language Book Society, 1978
Buku Teks
Batten,T.R.
Oxford University Press, 1960
Buku Teks
Sie, Kwat Soen
Centre for Agricultural Publications and Documentation, 1968
Buku Teks
Mackintosh, A.S.
Cambridge University Press , 1963
Buku Teks
by H.B. Chenery ... [et al.]
Universitaire Pers Rotterdam, 1967
Buku Teks