Salvatore, Dominick
John Wiley & Sons, 2007
Buku Teks
by George Zis ... [et al.]
Longman, 1988
Buku Teks
Appleyard, Dennis R.
McGraw-Hill, 2014
Buku Teks
Krugman, Paul R.
Pearson Education , 2014
Buku Teks
Kreinin, Mordechai Elihau
Harcourt Brace Jovanovich, 1975
Buku Teks