31. Columbia University Rare Book & Manuscript Library, MS X893.19 K71 no. 19 DS ID: DS19612 Title: Letter and Hebrew text Author: Yisʹrael Avraham Place: Ukraine Date: 1865.
32. Columbia University Rare Book & Manuscript Library, MS X893 F51 DS ID: DS19704 Title: Letter and Hebrew text Author: Abraham Firkovich Place: Karasu and Turkey Date: 1846.