Azyumardi Azra, Saiful Umam, editor
Indonesian-Netherlands Cooperation in Islamic Studies, 1998
Buku Referensi
editor, Martin L. Sinaga
Gramedia Widiasarana Indonesia, 2000
Buku Teks
Coward, Harold
Kanisius, 1989
Buku Teks
Halawa, Ohiao
Nias, 1993
Buku Referensi
Komaruddin Hidayat
Gramedia Pustaka Utama, 2003
Buku Teks