Columbia subject headings:
Library of Congress. National Library Service for the Blind and Physically Handicapped--History.
Talking book machines--Repairing--Societies, etc.--History.
Telephone Pioneers of America--History.
Harvard subject headings:
Library of Congress. National Library Service for the Blind and Physically Handicapped--History.
Talking book machines--Repairing--Societies, etc.--History.
Telephone Pioneers of America--History.
Princeton subject headings: