Helmberger, Peter G.
McGraw-Hill, 1991
Buku Teks
Starr, Philip C.
Wadsworth, 1984
Buku Teks
Brown, Maxwell L.
John Hopkins University Press, 1979
Buku Teks
Artikel Jurnal
Bayu Kharisma
Faculty of Economics and Business State Islamic University (UIN) Syarif Hidayatullah, 2019
Artikel Jurnal