Sorrell, P. (1979). Studies in the treatment of theme and its sources in some Old English narrative poems. University of Cambridge.
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)Sorrell, Paul. Studies in the Treatment of Theme and Its Sources in Some Old English Narrative Poems. University of Cambridge, 1979.
توثيق جمعية اللغة المعاصرة MLA (الطبعة الثامنة)Sorrell, Paul. Studies in the Treatment of Theme and Its Sources in Some Old English Narrative Poems. University of Cambridge, 1979.
تحذير: قد لا تكون هذه الاستشهادات دائما دقيقة بنسبة 100%.