The topological classification of germs of the maximum and minimax functions of a family of functions in general position
V. I. Matov

References
1.	V. I. Arnold, “On some problems in singularity theory”, Geometry and Analysis, Indian Academy of Sciences, Bangalore, 1980, 1–10
2.	L. N. Bryzgalova, Osobennosti funktsii maksimuma, Dissertatsiya, MGU, M., 1978