Pampillón Olmedo, Rafael2011-09-192011-09-191989-09-19http://hdl.handle.net/10637/506En: Revista de Estudios Agro-sociales. 1989. N. 149, pp 137-153, ISSN 0034-8155application/pdfspArtículohttp://creativecommons.org/licenses/by-nc-nd/4.0/deed.eshttps://creativecommons.org/licenses/by-nc-nd/4.0/deed.es