Columbia subject headings:
Harvard subject headings:
Chinese language--Honorific.
Chinese letters--History and criticism.
German language--Honorific.
German letters--History and criticism.
Princeton subject headings:
Chinese language--Grammar, Comparative--German.
Chinese language--Style.
Etiquette--China.
Etiquette--Germany.
German language--Grammar, Comparative--Chinese.
German language--Style.
Letter writing, Chinese.
Letter writing, German.