Cita APA (7a ed.)
(1997). Petroleum Geo-Services: Annual report 1997. PGS.
Cita Chicago Style (17a ed.)
Petroleum Geo-Services: Annual Report 1997. Oslo: PGS, 1997.
Cita MLA (9a ed.)
Petroleum Geo-Services: Annual Report 1997. PGS, 1997.
Precaución: Estas citas no son 100% exactas.