Allen, A. F. (1920). An introduction to chemical engineering: An elementary textbook for the use of students and users of chemical machinery. Sir Isaac Pitman and Sons Ltd.
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)Allen, Alfred Frederick. An Introduction to Chemical Engineering: An Elementary Textbook for the Use of Students and Users of Chemical Machinery. Londres: Sir Isaac Pitman and Sons Ltd, 1920.
توثيق جمعية اللغة المعاصرة MLA (الإصدار التاسع)Allen, Alfred Frederick. An Introduction to Chemical Engineering: An Elementary Textbook for the Use of Students and Users of Chemical Machinery. Sir Isaac Pitman and Sons Ltd, 1920.
تحذير: قد لا تكون هذه الاستشهادات دائما دقيقة بنسبة 100%.