^Collison, Robert Lewis. Encyclopaedias: their history throughout the ages; a bibliographical guide with extensive historical notes to the general encyclopaedias issued throughout the world from 350 B.C. to the present day. New York, Hafner (1966), p. 112.
^Collison, Robert Lewis. Encyclopaedias: their history throughout the ages; a bibliographical guide with extensive historical notes to the general encyclopaedias issued throughout the world from 350 B.C. to the present day. New York, Hafner (1966), p. 112.