Rob Woodhall.„Relative hills on Earth“. TheRelativeHillsofBritain (18-may 2016-yil). — „Ultra: peaks with a minimum prominence/relative height of 1500m. Steve Fry coined the term Ultra in the USA in the 1980s. His original term was 'ultra major mountain'. There are no Ultra summits in Britain. Hall of Fame entry minimum is 15.“.
