Columbia subject headings:
Agostino di Duccio, 1418-1481?--Criticism and interpretation.
Gates--Italy--Perugia.
Perugia (Italy)--Buildings, structures, etc.
Porta San Pietro (Perugia, Italy)
Harvard subject headings:
Agostino di Duccio, 1418-1481?
Architecture, Classical--Influence.
Gates--Italy--Perugia.
Perugia (Italy)--Buildings, structures, etc.
Porta San Pietro (Perugia, Italy)
Princeton subject headings:
Agostino di Duccio, 1418-1481?--Criticism and interpretation.
Gates--Italy--Perugia.
Perugia (Italy)--Buildings, structures, etc.
Porta San Pietro (Perugia, Italy)