University of Maryland, College Park. School of Library and Information Services, Wellisch, H. H., & Wilson, T. D. (1972). Subject retrieval in the seventies: New directions ; Proceedings of an international symposium held at the center of adult education university of maryland college park May 14 to 15, 1971. Greenwood Publishing Company..
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)University of Maryland, College Park. School of Library and Information Services, Hans H. Wellisch, و Thomas D. Wilson. Subject Retrieval in the Seventies: New Directions ; Proceedings of an International Symposium Held at the Center of Adult Education University of Maryland College Park May 14 to 15, 1971. Westport, Connecticut.: Greenwood Publishing Company., 1972.
توثيق جمعية اللغة المعاصرة MLA (الطبعة الثامنة)University of Maryland, College Park. School of Library and Information Services, et al. Subject Retrieval in the Seventies: New Directions ; Proceedings of an International Symposium Held at the Center of Adult Education University of Maryland College Park May 14 to 15, 1971. Greenwood Publishing Company., 1972.