Stevens, N. D. (1961). A comparative study of three systems of information retrieval. Graduate School of Library Service, Rutgers, The State University.
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)Stevens, Norman D. A Comparative Study of Three Systems of Information Retrieval. New Brunswick, N.J.: Graduate School of Library Service, Rutgers, The State University, 1961.
توثيق جمعية اللغة المعاصرة MLA (الطبعة الثامنة)Stevens, Norman D. A Comparative Study of Three Systems of Information Retrieval. Graduate School of Library Service, Rutgers, The State University, 1961.
تحذير: قد لا تكون هذه الاستشهادات دائما دقيقة بنسبة 100%.