Alighieri, Dante
The Divine comedy / Dante Alighieri
Everyman's Library , 1995
 Buku Teks
The Harvard classics: volume 20, the divine comedy of Dante Alighieri / editor, Charles W. Eliot
Grolier Enterprises Corp., 1995
 Buku Referensi
The Harvard classics: volume 20, the divine comedy of Dante Alighieri / editor, Charles W. Eliot
Grolier Enterprises Corp, 1995
 Buku Teks
The harvarvard classics: the divine comedy of dante alighieri / editor, Charles W. Eliot dan Henry F. Cary
Grolier Enterprises Corp., 1995
 Buku Referensi
Muhammad Iqbal Ramadhan
Study case: Delta/signal corporation business strategy (Harvard Business School) = Strategi bisnis Delta/Signal korporasi
Fakultas Ekonomi dan Bisnis Universitas Indonesia, 2019
 UI - Makalah dan Kertas Kerja