1. Columbia University Rare Book & Manuscript Library, MS X893 Z8 v.2 no.3 DS ID: DS18606 Title: Responsa Author: Ishmael ben Abraham Isaac ha-Kohen Place: Italy Date: 17--
2. Columbia University Rare Book & Manuscript Library, MS X893 P64 DS ID: DS19906 Title: Responsa Place: Italy Date: 18--