Columbia subject headings:
Architecture, Byzantine--Turkey--Istanbul.
Church architecture--Turkey--Istanbul.
Church buildings--Turkey--Istanbul--Pictorial works.
Harvard subject headings:
Architecture, Byzantine--Turkey--Istanbul
Church architecture--Turkey--Istanbul.
Church buildings--Turkey--Istanbul--Pictorial works.
Istanbul (Turkey)--Buildings, structures, etc.--Pictorial works.
Istanbul (Turkey)--Churches--Pictorial works.
Princeton subject headings:
Architecture, Byzantine--Turkey--Istanbul.
Church architecture--Turkey--Istanbul.
Church buildings--Turkey--Istanbul--Pictorial works.