APA (7th ed.) Zitazioa
Duff, E. Social Order: February 1961. The Institute of Social Order.
Chicago Style (17th ed.) Zitazioa
Duff, Edward. Social Order: February 1961. Saint Louis, EUA: The Institute of Social Order.
MLA (9th ed.) Zitazioa
Duff, Edward. Social Order: February 1961. The Institute of Social Order.
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