Columbia subject headings:
Jechielis bar Abrahami, -approximately 1070.
Piyutim--History and criticism.
Harvard subject headings:
Piyutim--History and criticism.
Yeḥiʼel ben Avraham, mi-Roma
Princeton subject headings:
Jechielis bar Abrahami, -approximately 1070--Criticism and interpretation.
Piyutim--Early works to 1800.
Piyutim--History and criticism.