APA

Kraa J. A. d., Shell International Petroleum Company, World Petroleum Congress (13th. : 1991 : Buenos Aires) & Shell International Petroleum Company.Advances in natural gas processing technology. : .

Chicago

Kraa J A de, Shell International Petroleum Company, World Petroleum Congress (13th. : 1991 : Buenos Aires) and Shell International Petroleum Company.Advances in natural gas processing technology. : .

Harvard

Kraa J. A. d., Shell International Petroleum Company, World Petroleum Congress (13th. : 1991 : Buenos Aires) and Shell International Petroleum Company.Advances in natural gas processing technology. : .

MLA

Kraa J A de, Shell International Petroleum Company, World Petroleum Congress (13th. : 1991 : Buenos Aires) and Shell International Petroleum Company.: . .