APA

Ahmad I., Zughaid M., World Petroleum Congress (17th. : 2002 sept. 1-5 : Río de Janeiro B. & Zughaid M.Refining in new millennium. : .

Chicago

Ahmad Iftikhar, Zughaid Muftah, World Petroleum Congress (17th. : 2002 sept. 1-5 : Río de Janeiro Brasil) and Zughaid Muftah.Refining in new millennium. : .

Harvard

Ahmad I., Zughaid M., World Petroleum Congress (17th. : 2002 sept. 1-5 : Río de Janeiro B. and Zughaid M.Refining in new millennium. : .

MLA

Ahmad Iftikhar, Zughaid Muftah, World Petroleum Congress (17th. : 2002 sept. 1-5 : Río de Janeiro Brasil) and Zughaid Muftah.: . .