Source: http://www.univ-bejaia.dz/jspui/bitstream/123456789/1998/1/L%E2%80%99impact%20de%20la%20nouvel%20politique%20commerciale%20sur%20l%E2%80%99activit%C3%A9%20des%20entreprises%20productives%20en%20Alg%C3%A9rie.pdf