Ewen, F. (1969). Bertolt Brecht: His life, his art, and his times. Citadel Press.
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)Ewen, Frederic. Bertolt Brecht: His Life, His Art, and His Times. New York: Citadel Press, 1969.
توثيق جمعية اللغة المعاصرة MLA (الإصدار التاسع)Ewen, Frederic. Bertolt Brecht: His Life, His Art, and His Times. Citadel Press, 1969.
تحذير: قد لا تكون هذه الاستشهادات دائما دقيقة بنسبة 100%.