Michaels, Ralf MPI for Comparative and International Private Law, Max Planck Society;
https://scholarship.law.duke.edu/cgi/viewcontent.cgi?article=1293&context=djcil (Any fulltext)
Michaels, R., & Pauwelyn, J. (2012). Conflict of Norms or Conflict of Laws?: Different Techniques in the Fragmentation of Public International Law. Duke Journal of Comparative & International Law, 22, 349-376.