APA

Booth M., Shannon I., Shell, World Petroleum Congress (15th. : 1997 : Beijing), Shannon I. & Shell.The continuing evolution of environmentally enhanced petroleum products. : .

Chicago

Booth Martin, Shannon Ian, Shell, World Petroleum Congress (15th. : 1997 : Beijing), Shannon Ian and Shell.The continuing evolution of environmentally enhanced petroleum products. : .

Harvard

Booth M., Shannon I., Shell, World Petroleum Congress (15th. : 1997 : Beijing), Shannon I. and Shell.The continuing evolution of environmentally enhanced petroleum products. : .

MLA

Booth Martin, Shannon Ian, Shell, World Petroleum Congress (15th. : 1997 : Beijing), Shannon Ian and Shell.: . .