Columbia subject headings:
Harvard subject headings:
Architecture, Early Christian--Congresses.
Art, Early Christian--Congresses.
Christian antiquities--Great Britain--Congresses.
Christian antiquities--Middle East--Congresses.
Church architecture--Great Britain--Congresses
Church architecture--Middle East--Congresses.
Church history--Primitive and early church, ca. 30-600--Congresses.
Princeton subject headings:
Christian antiquities--Congresses.
Church architecture--History--Congresses.