Guide de randonnée (en anglais) - Trekking the Corsica GR20 : Two-way Trekking Guide | Knife Edge OutdoorGuide de randonnes (en anglais) pour parcourir le clbre GR20 en Corse. Description fournie par l'diteur : The only two way guidebook to the GR20: both northbound and southbound routes are described in full. Real IGN Maps included (1: 25,000): no need to carry separate maps. 15 different itineraries: schedules of 9, 10, 11, 12, 13, 14, 15 and 16 days. Includes both northbound and southbound itineraries. Difficult calculations of time, distance and