Columbia subject headings:
Bibliographers--Great Britain--Biography.
British Museum--Officials and employees--Biography.
Incunabula--Bibliography--Methodology.
Proctor, Robert, 1868-1903.
Harvard subject headings:
Bibliographers--Great Britain--Biography.
British Museum--Officials and employees--Biography.
British Museum. Department of Printed Books--Biography.
Incunabula--Bibliography--Methodology
Proctor, Robert, 1868-
Proctor, Robert, 1868-1903.
Princeton subject headings:
Proctor, Robert, 1868-1903.