Columbia subject headings:
Harvard subject headings:
Amoraim.
Geonim.
Mishnah--History.
Saboraim.
Sherira ben Hanina, gaon, approximately 906-1006. Igeret Rav Sherira Gaʼon.
Talmud--History.
Tannaim.
Princeton subject headings:
Amoraim.
Geonim.
Mishnah--History.
Saboraim.
Sherira ben Hanina, Gaʼon, c. 906-1006. Igeret.
Talmud--History.
Tannaim.