1. Bourbaki, N.: Topologie générale, Chap. I, 3. ed. Paris: Hermann 1961.
2. ?? Topologie générale, Chap. III, 3. ed. Paris: Hermann 1960.
3. Cartan, H.: Quotient d'un espace analytique par un groupe d' automorphismes. Algebraic Geometry and Topology. A symposium in honor ofS. Lefschetz. S. 90?102. Princeton University Press 1957.
4. -- Quotients of complex analytic spaces. Contributions to Function Theory. International Colloquium on Function Theory, Tata Institute of Fundamental Research. Bombay 1960.
5. Fourès, L.: Determination of an automorphic function for a given analytic equivalence relation. Seminars on Analytic Functions, Seminar III-Riemann Surfaces. Institute for Advanced Study. Princeton 1957.