Bert Jüttler,
"Arbitrarily weak linear convexity conditions for multivariate polynomials"
, in Studia Scientiarum Mathematicarum Hungarica, Vol. 36, Seite(n) 165-183, 2000, ISSN: 1588-2896
Original Titel:
Arbitrarily weak linear convexity conditions for multivariate polynomials