References
- Bredon , GE . 1993 . Topology and Geometry , New York : Springer-Verlag .
- Fomenko , AT and Fuks , DB . 1989 . A Course in Homotopic Topology , Izd. Nauka . (In Russian; an English translation of an earlier version was published by Academiai Kiado, Budapest, 1986.)
- Rockafellar , RT . 1990 . Convex Analysis , Princeton, New Jersey : Princeton University Press .