Heller, Monica
Routledge, Taylor & Francis Group, 2018
Buku Teks SO
Briggs, Charles L.
Cambridge University Press, 1997
eBooks
Fitri Yani Jalil
Faculty of Economics and Business State Islamic University (UIN) Syarif Hidayatullah, 2018
Artikel Jurnal
Hernandez-Campoy, Juan Manuel
Wiley Blackwell, 2016
Buku Teks SO
Hanssmann, Fred
John Wiley & Sons, 1962
Buku Teks SO