Facilitating hikers' mobility in protected areas through smartphone app: a case of the Hoge Kempen National Park, Belgium. - Muhammad Shaker; Elke Hermans; Veerle Cops; Yves Vanrompay; Muhammad Adnan 003; Roeland Maes; Ansar-Ul-Haque Yasar (Pers. Ubiquitous Comput., 2021)