On hypersurfaces embedded in euclidean space with positive constant $H_r$ curvature Barbara NelliBeate Semmler 53A1035J60H_r-surfacescalar curvaturestrictly convex boundarycurvature estimatesAlexandrov reflection Indiana University Mathematics Journal 2001 text pdf 10.1512/iumj.2001.50.1898 10.1512/iumj.2001.50.1898 en Indiana Univ. Math. J. 50 (2001) 989 - 1002 state-of-the-art mathematics http://iumj.org/access/