APA

Erkens. E, Concawe & Erkens. E. (1998). Classification and labelling of petroleum substances according th the EU dangerous substances directive (revision 1). Brussels: Concawe.

Chicago

Erkens. E, Concawe and Erkens. E. 1998. Classification and labelling of petroleum substances according th the EU dangerous substances directive (revision 1). Brussels: Concawe.

Harvard

Erkens. E, Concawe and Erkens. E. (1998). Classification and labelling of petroleum substances according th the EU dangerous substances directive (revision 1). Brussels: Concawe.

MLA

Erkens. E, Concawe and Erkens. E. Classification and labelling of petroleum substances according th the EU dangerous substances directive (revision 1). Brussels: Concawe. 1998.