See, in particular, the judgment of the Court of Justice of 3 June 1986, R. H. Kempf v Staatssecretaris van Justitie, C-139/85, ECLI:EU:C:1986:223, paragraph 13.
Féach, go háirithe, breithiúnas na Cúirte Breithiúnais an 3 Meitheamh 1986, R. H. Kempf v Staatssecretaris van Justitie, C-139/85, ECLI:EU:C:1986:223, mír 13.