1. Columbia University Rare Book & Manuscript Library, MS Or 11 DS ID: DS6598 Title: Sī faṣl Author: Nasir al-Din al-Tusi Date: 16--?-17--?
2. Princeton University, Islamic Manuscripts New Series no. 499 DS ID: DS13365 Title: Sī faṣl Author: Nasir al-Din al-Tusi Date: between 17--? and 1803?