International Conference on Spectral Theory of Differential Operators, Knowles, I. W., & Lewis, R. T. (1981). Spectral theory of differential operators: Proceedings of the conference held at the University of Alabama in Birmingham, Birmingham, Alabama, U.S.A., March 26-28, 1981. North-Holland ; Sole distributors for the U.S.A. and Canada, Elsevier North-Holland.
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)International Conference on Spectral Theory of Differential Operators, Ian W. Knowles, و Roger T. Lewis. Spectral Theory of Differential Operators: Proceedings of the Conference Held at the University of Alabama in Birmingham, Birmingham, Alabama, U.S.A., March 26-28, 1981. Amsterdam ; New York : New York, N.Y.: North-Holland ; Sole distributors for the U.S.A. and Canada, Elsevier North-Holland, 1981.
توثيق جمعية اللغة المعاصرة MLA (الطبعة الثامنة)International Conference on Spectral Theory of Differential Operators, et al. Spectral Theory of Differential Operators: Proceedings of the Conference Held at the University of Alabama in Birmingham, Birmingham, Alabama, U.S.A., March 26-28, 1981. North-Holland ; Sole distributors for the U.S.A. and Canada, Elsevier North-Holland, 1981.