Department of Mathematics, Faculty of Science, Okayama University Acta Medica Okayama 0030-1566 39 1 1997 Warped Products and Riemannian Manifolds Admitting a Function Whose Gradient is of Constant Norm 165 185 EN Takashi Sakai 10.18926/mjou/33580 No potential conflict of interest relevant to this article was reported.

Department of Mathematics, Faculty of Science, Okayama University Acta Medica Okayama 0030-1566 27 1 1985 On quasiconvexity and contractibility of domains in R^n 221 227 EN Jin-ichi Itoh Takashi Sakai 10.18926/mjou/33430 No potential conflict of interest relevant to this article was reported.

Department of Mathematics, Faculty of Science, Okayama University Acta Medica Okayama 0030-1566 25 1 1983 On continuity of injectivity radius function 91 97 EN Takashi Sakai 10.18926/mjou/33382 No potential conflict of interest relevant to this article was reported.

Department of Mathematics, Faculty of Science, Okayama University Acta Medica Okayama 0030-1566 49 1 2007 Cut Loci and Distance Functions 65 92 EN Jin-ichi Itoh Takashi Sakai 10.18926/mjou/33118 No potential conflict of interest relevant to this article was reported.