Fitch, W. S. (1976). Multiple Periodic Variable Stars: Proceedings of the International Astronomical Union Colloquium No. 29, Held at Budapest, Hungary 1–5 September 1975. Springer Netherlands. https://doi.org/10.1007/978-94-010-1175-4
Chicago-Zitierstil (17. Ausg.)Fitch, Walter S. Multiple Periodic Variable Stars: Proceedings of the International Astronomical Union Colloquium No. 29, Held at Budapest, Hungary 1–5 September 1975. Dordrecht: Springer Netherlands, 1976. https://doi.org/10.1007/978-94-010-1175-4.
MLA-Zitierstil (9. Ausg.)Fitch, Walter S. Multiple Periodic Variable Stars: Proceedings of the International Astronomical Union Colloquium No. 29, Held at Budapest, Hungary 1–5 September 1975. Springer Netherlands, 1976. https://doi.org/10.1007/978-94-010-1175-4.