McStay, Andrew
Sage, 2017
Buku Teks
Nadia Primasanti
Fakultas Teknik Universitas Indonesia, 2006
UI - Skripsi Membership
Jones, Marsha
Palgrave, 1999
Buku Teks
Wacks, Raymond
Oxford University Press, 2013
Buku Teks
Wilson, Stan Le Roy
McGraw-Hill, 1995
Buku Teks