Dumaine, Brain. Billionaires vs big oil / by Brian Dumaine. - Hong Kong: Time Asia Limited, May 1, 2015. - pages 56-62 26.8cm. - Monthly. - Volume 171, Number 6 (May 1, 2015) - Fortune. page 56-62 Volume 171 Number 6 (May 1, 2015) 0738-5587 . ISSN: 0738-5587 Subjects--Topical Terms: Entrepreneurs Dewey Class. No.: BPer. 650.0519 / F77 2015