Columbia subject headings:
Harvard subject headings:
Art--Collectors and collecting--Correspondence.
Businessmen--Correspondence.
Essayan, Michael--Correspondence.
Gulbenkian, Calouste Sarkis--Correspondence.
Princeton subject headings:
Art--Collectors and collecting--Correspondence.
Businessmen--Correspondence.
Essayan, Mikaël, 1927-2012--Correspondence.
Gulbenkian, Calouste Sarkis--Correspondance.