Castermans is Professor of Private Law at Leiden University. He is interested in the interaction between European Law and Dutch private law as well as the interaction between national private and public law, because every day cases show how difficult it is to reconcile rules of different sources.
- The legal liability of Dutch parent companies for subsidiaries’ involvement in violations of fundamental, internationally recognised rights (2009)
- Towards a European Contract Law through Social Dialogue. European Review of Contract Law, 2011/7 (2), pp. 360-368. (2011)