Columbia subject headings:
Civilization, Medieval--Sources.
Encyclopedias and dictionaries--Early works to 1600.
Science, Medieval--History--Sources.
Harvard subject headings:
Civilization, Medieval--Sources
Encyclopedias and dictionaries--Early works to 1600
Science, Medieval--Sources.
Princeton subject headings:
Civilization, Medieval--Sources.
Encyclopedias and dictionaries--Early works to 1600.
Science, Medieval--Sources.