Bibliography

1

H. Weyl, ``Über gewöhnliche Differentialgleichungen mit Singularitäten und die zugehörige Entwicklungen willkurlicher Funktionen,'' Mathematische Annalen 68 220-269 (1910).

2

H.V. McIntosh, ``Quantization as an Eigenvalue Problem,'' in Group Theory and its Applications (E.M. Loebl, ed.), Academic Press, New York, 1975. pp 333-368.

3

George D. Birkhoff and Rudolph E. Langer, ``The Boundary Problems and Developments Associated with a System of Ordinary Linear Differential Equations of the First Order,'' Proceedings of the American Academy of Arts and Sciences 58 49-128 (1923).

Reprinted in Collected Mathematical Papers of George David Birkhoff, Dover Publications Inc., New York, 1968. pp.345-424.

4

F.R. Gantmacher, The Theory of Matrices, Chelsea Publishing Company, New York, 1959. Volume II, pp. 125-131.