• J.D. Crawford, M. Golubitsky, M.G.M. Gomes, E. Knobloch and I.N. Stewart. Boundary conditions as symmetry constraints. In: Singularity Theory and Its Applications, Warwick 1989, Part II. (M. Roberts and I.N. Stewart, eds.) Lecture Notes in Math. 1463 Springer-Verlag, Heidelberg, 1991, 63-79. [Abstract] [PDF 584K]