NH. Dini
Langit dan bumi sahabat kami cerita kenangan
Gramedia, [date of publication not identified]
Buku Teks SO
Liber Amicorum : buku kesan dan kenangan dari para sahabat
Yayasan Pustaka Obor Indonesia, 2015
Buku Teks SO
Gustin Suradji
Sahabat-sahabat / Gustin Suradji
Gramedia Pustaka Utama, 1991
Buku Teks SO
Why outsourcing is our friend
Artikel Jurnal
Baker, Ross K.
Friend and Foe In the U.S. Senate
Free Press, 1980
Buku Teks SO