ALFONSO, Ramon. GRIGG, D. An Introduction to Agricultural Geography. Documents d’Anàlisi Geogràfica, [S. l.], v. 7, p. 209–212, 1985. DOI: 10.5565/rev/dag.1379. Disponível em: https://dag.revista.uab.cat/article/view/v7-alfonso. Acesso em: 8 sep. 2025.