 Egbert Brieskorn found simple algebraic equations for 28 complex hypersurfaces in complex 5-space such that their intersection with a small sphere of dimension 9 around a singular point is diffeomorphic to these exotic spheres.Subsequently, Milnor worked on the topology of isolated singular points of complex hypersurfaces in general, developing the theory of the Milnor fibration whose fiber has the homotopy type of a bouquet of "μ" spheres where "μ" is known as the Milnor number.Milnor's 1968 book on his theory inspired the growth of a huge and rich research area that continues to mature to this day.