Quantifying accessibility to Palaeolithic rock art: methodological proposal for the study of human transit in Atxurra Cave (Northern Spain) - Intxaurbe Alberdi, Iñaki; Arriolabengoa, Martín; Medina-Alcaide, María Ángeles; Rivero, Olivia; Ríos Garaizar, Joseba; Salazar Cañarte, Sergio; Líbano, Iñaki; Gárate Maidagán, Diego (2021)