ON COMPLETE OPEN MANIFOLDS WITH NON-NEGATIVE CURVATURE ALONG RAY DIRECTIONS - 徐森林 梅加强 (Acta mathematica scientia, 1998)
Keywords: Busemann function; Busemanu; convex; convex function; end; exhaustion; exhaustion function; function; Subharmonic; Subharmonic function; convex function; Subharmonic function; end; exhaustion function; Busemann function