APA

Shell Briefing Service. SBS 5:1991, . (1991). The tanker industry in the 1990s. London: Shell Briefing Service. SBS 5:1991.

Chicago

Shell Briefing Service. SBS 5:1991, . 1991. The tanker industry in the 1990s. London: Shell Briefing Service. SBS 5:1991.

Harvard

Shell Briefing Service. SBS 5:1991, . (1991). The tanker industry in the 1990s. London: Shell Briefing Service. SBS 5:1991.

MLA

Shell Briefing Service. SBS 5:1991, . The tanker industry in the 1990s. London: Shell Briefing Service. SBS 5:1991. 1991.