Salvatore, Dominick, author
John Wiley & Sons, 2007
Buku Teks
Walter, Ingo, author
John Wiley & Sons, 1981
Buku Teks
by George Zis ... [et al.]
Longman, 1988
Buku Teks
Appleyard, Dennis R., author
McGraw-Hill, 2014
Buku Teks
Krugman, Paul R., author
Pearson Education , 2014
Buku Teks