Columbia subject headings:
Telephone--Canada--History.
Telephone--Ontario--History.
Telephone--Québec (Province)--History.
Harvard subject headings:
Telephone operators--Ontario--History.
Telephone operators--Québec (Province)--History.
Telephone--Ontario--History.
Telephone--Québec (Province)--History.
Telephone--Social aspects--Ontario--History.
Telephone--Social aspects--Québec (Province)--History.
Women--Employment--Effect of technological innovations on.
Princeton subject headings:
Telephone--Ontario--History.
Telephone--Québec (Province)--History.