Lyons, Kate (21 May 2017). “Mount Everest's Hillary Step has collapsed, mountaineer confirms”. TheGuardian.com. 22 May 2017閲覧。 “Mosedale, who reached Everest’s summit for the sixth time on 16 May, posted a photograph of what remains of the Hillary Step when he returned to base camp. It shows the topography has changed significantly compared with photographs taken a few years ago.”
