APA Style

Chittick, W, C., Nasr, S, H. (2007). The essential Seyyed Hossein Nasr . Bloomington, Ind. :: World Wisdom, Inc.

MLA Style

Chittick, William, C.., Nasr, Seyyed, Hossein.. "The essential Seyyed Hossein Nasr". Bloomington, Ind. :: World Wisdom, Inc, 2007. Text.