Columbia subject headings:
Canada--Politics and government--Handbooks, manuals, etc.
Social service--Periodicals--Directories.
Trade associations--Canada--Directories.
Trade associations--United States--Directories.
United States--Politics and government--Handbooks, manuals, etc.
Harvard subject headings:
Canada--Politics and government--Handbooks, manuals, etc.
Professional associations--Canada--Directories.
Professional associations--United States--Directories.
Social service--Societies, etc.--Directories
United States--Politics and government--Handbooks, manuals, etc.
Princeton subject headings: