Wardiningsih Soerjohardjo, author
Serat Alam Media, 2017
Buku Teks
Wolff, Robert Lee, author
Garland Publishing, 1981
Buku Referensi
Harvard Business Review, 1960
Buku Teks
Virtue and Company Limited , 1977
Buku Teks
Tan Malaka, author
Yayasan Massa , 1980
Buku Teks