Columbia subject headings:
Byzantine antiquities--Congresses.
Classical antiquities--Congresses.
Excavations (Archaeology)--Bulgaria--Nicopolis ad Istrum (Extinct city)--Congresses.
Nicopolis ad Istrum (Extinct city)--Congresses.
Harvard subject headings:
Byzantine antiquities--Congresses.
Classical antiquities--Congresses.
Excavations (Archaeology)--Bulgaria--Nicopolis ad Istrum (Extinct city)--Congresses.
Nicopolis ad Istrum (Extinct city)--Congresses.
Princeton subject headings:
Byzantine antiquities--Congresses.
Classical antiquities--Congresses.
Excavations (Archaeology)--Bulgaria--Nicopolis ad Istrum (Extinct city)--Congresses.
Nicopolis ad Istrum (Extinct city)--Congresses.