Não informado. (2001). Shell world. Shell International Petroleum.
Chicagoスタイル(17版)引用形式Não informado. Shell World. London: Shell International Petroleum, 2001.
MLA(8版)引用形式Não informado. Shell World. Shell International Petroleum, 2001.
警告: この引用は必ずしも正確ではありません.