Columbia subject headings:
Archives--Maryland--Baltimore--Directories.
Baltimore (Md.)--History--Archival resources--Maryland--Baltimore.
Maryland--History--Archival resources--Maryland--Baltimore.
Harvard subject headings:
Archives--Maryland--Baltimore--Directories.
Baltimore (Md.)--History--Archival resources--Maryland--Baltimore.
Maryland--History--Archival resources--Maryland--Baltimore.
Princeton subject headings:
Archives--Maryland--Baltimore--Directories.
Baltimore (Md.)--History--Archival resoruces--Maryland--Baltimore.
Maryland--History--Archival resources--Maryland--Baltimore.