Several authors have taken an interest in the use of the articles in Hegel's works, among them Leonard Nelson, M. Heidegger, and the Dutch authors J.A. Oosterbaan and W. van Dooren. Heidegger and Oosterbaan are both convinced that there is some system in Hegel's use of articles, especially in his use of definite articles in titles of chapters, but van Dooren has no confidence in the possibility of discerning any systematic features here (van Dooren 1965/143).