What is the fine-grained topic of the following text: He led this study with Boris Cheval of the University of Geneva, and their international team of researchers from the University of Oxford (Eda Tipura), the University of Geneva (Nicolas Burra, Jaromil Frossard, Dan Orsholits), and the Université Côte d’Azur (Rémi Radel). Only return the topic.
International research study collaboration