Ball, Jeffrey. The of mexico's (black) gold / by Jeffrey Ball. - Hong Kong: Time Asia Limited, September 1, 2014. - pages 40-46 26.8cm. - Monthly. - Volume 170, number 3 (September 1, 2014) - Fortune. . - Fortune Volume 170 Number 3 0738-5587 . ISSN: 0738-5587 Dewey Class. No.: BPer. / F77