Wright, Philip G.
The American tariff and oriental trade / by Philip G. Wright
The University of Chicago Press, 1931
 Buku Teks
Gupta, K.R.
A Study of general agreement on tariffs and trade
S. Chand, 1967
 Buku Teks
Crosby, Philip B.
Quality is free: the art of making quality certain Philip
McGraw-Hill, 1979
 Buku Teks SO
Gill, Philip E.
Practical optimization/Philip E. Gill, Walter Murray, Margaret H. Wright
Academic Press , 1981
 Buku Teks SO
Pacific trade in services
edited by Leslie V. Castle, Christopher Findlay
Allen & Unwin, 1988
 Buku Referensi