1. INRA, Thiverval-Grignon, France
2. King’s College London, London, United Kingdom
3. Max Planck Digital Library
4. Faculty of Mathematics, University of Belgrade, Belgrade, Serbia
5. INRIA, ORSAY Cedex, France
6. Mathematical Institute of the Serbian Academy of Sciences and Arts, Belgrade, Serbia
7. Faculty of Humanities, University of Bern, Bern, Switzerland
8. University of Göttingen, Göttingen, Germany