Source: https://www.researchgate.net/profile/Aicha-Merzaia/publication/318982749_La_filiere_datte_dans_la_region_de_Tidikelt_entre_le_passe_et_le_present/links/59895d55aca27266adac5c25/La-filiere-datte-dans-la-region-de-Tidikelt-entre-le-passe-et-le-present.pdf