Columbia subject headings:
Gray, John Morgan, 1907-1978.
Macmillan Company of Canada--History.
Publishers and publishing--Canada--Biography.
Harvard subject headings:
Gray, John Morgan.
Macmillan Company of Canada--History.
Publishers and publishing--Canada--Biography.
Princeton subject headings:
Gray, John Morgan.
Macmillan Company of Canada--History.
Publishers and publishing--Canada--Biography.