Duffield, A. J. (1877). Peru in the guano age. Being a short account of a recent visit to the guano deposits with some reflections on the money they have produced and the uses to wich it has been applied (1a. ed.). Richard Bentley and son, publishers in ordinary to Her Majestiy the Queen.
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)Duffield, A. J. Peru in the Guano Age. Being a Short Account of a Recent Visit to the Guano Deposits with Some Reflections on the Money They Have Produced and the Uses to Wich It Has Been Applied. 1a. ed. Londres: Richard Bentley and son, publishers in ordinary to Her Majestiy the Queen, 1877.
توثيق جمعية اللغة المعاصرة MLA (الإصدار التاسع)Duffield, A. J. Peru in the Guano Age. Being a Short Account of a Recent Visit to the Guano Deposits with Some Reflections on the Money They Have Produced and the Uses to Wich It Has Been Applied. 1a. ed. Richard Bentley and son, publishers in ordinary to Her Majestiy the Queen, 1877.