الاربعون في اصول الدين / فخر الدين الرازي. الاربعين في امامة الطاهرين / محمد طاهر بن محمد طاهر بن محمد حسين الشيرازي ثم النجفي.

Manuscripts of the Islamic World offers a curated selection of extraordinary manuscripts hosted or held by Princeton University Library. The manuscripts are predominantly in Arabic, but there are also many in Persian and Ottoman Turkish. The manuscript digitizations here are a fraction of the full Manuscripts of the Islamic World collections, housed in Special Collections in Princeton's Firestone Library. Efforts are ongoing to make the manuscripts of these collections more accessible through conservation, catalog record updates, and digitization.