Illmer, Martin MPI for Comparative and International Private Law, Max Planck Society;
https://journals.law.uj.edu.pl/TPP/article/view/657 (Any fulltext)
Illmer, M. (2014). From Related Services to Services – Unchaining the CESL’s Substantive and Personal Scope with regard to Related Services. Transformacje Prawa Prywatnego, (3), 5-19.