Cross, Rod, author
Martin Robertson, 1982
Buku Teks
Berry, Craig, author
Palgrave Macmillan, 2016
Buku Teks
Krugman, Paul R., author
Addison-Wesley , 1997
Buku Teks
Tinbergen, Jan, 1903-, author
North-Holland Publishing , 1952
Buku Teks
Walker, E. Ronald, author
University of Chicago Press, 1947
Buku Teks