APA

Erkens. E, Concawe & Erkens. E. (2001). Classification and labelling of petroleum substances according to the EU dangerous substances directive (CONCAWE recommendations - August 2001). Brussels: Concawe.

Chicago

Erkens. E, Concawe and Erkens. E. 2001. Classification and labelling of petroleum substances according to the EU dangerous substances directive (CONCAWE recommendations - August 2001). Brussels: Concawe.

Harvard

Erkens. E, Concawe and Erkens. E. (2001). Classification and labelling of petroleum substances according to the EU dangerous substances directive (CONCAWE recommendations - August 2001). Brussels: Concawe.

MLA

Erkens. E, Concawe and Erkens. E. Classification and labelling of petroleum substances according to the EU dangerous substances directive (CONCAWE recommendations - August 2001). Brussels: Concawe. 2001.