Gilbert, P. T. (1921). The key to culture: Customs, manners and niceties of society. Geographical Pub.
Chicago-referens (17:e uppl.)Gilbert, Paul Thomas. The Key to Culture: Customs, Manners and Niceties of Society. Chicago: Geographical Pub, 1921.
MLA-referens (9:e uppl.)Gilbert, Paul Thomas. The Key to Culture: Customs, Manners and Niceties of Society. Geographical Pub, 1921.
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