George Fry & Associates. (1961). Study of circulation control systems: Public libraries, college and university libraries, special libraries. Library Technology Project of the American Library Association and the Council on Library Resources, INC.
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)George Fry & Associates. Study of Circulation Control Systems: Public Libraries, College and University Libraries, Special Libraries. Chicago: Library Technology Project of the American Library Association and the Council on Library Resources, INC, 1961.
توثيق جمعية اللغة المعاصرة MLA (الطبعة الثامنة)George Fry & Associates. Study of Circulation Control Systems: Public Libraries, College and University Libraries, Special Libraries. Library Technology Project of the American Library Association and the Council on Library Resources, INC, 1961.