Columbia subject headings:
French language--Dialects--France--Picardy--Bibliography.
French language--Dialects--France--Picardy--Dictionaries.
French language--Dialects--France--Picardy--Lexicography--History.
Harvard subject headings:
Encyclopedias and dictionaries, French--History and criticism.
French language--Dialects--France--Picardy.
French language--Lexicography
Princeton subject headings:
French language--Dialects--France--Picardy--Bibliography.
French language--Dialects--France--Picardy--Dictionaries.
French language--Dialects--France--Picardy--Lexicography--History.