Source: https://www.researchgate.net/profile/Zerbo-Adama/publication/5178521_Marche_du_travail_urbain_et_pauvrete_en_Afrique_subsaharienne_un_modele_d'analyse/links/0fcfd513df543368fc000000/Marche-du-travail-urbain-et-pauvrete-en-Afrique-subsaharienne-un-modele-danalyse.pdf