University of Odense (Denmark),
University of Cambridge (England),
University of Sussex (England),
University of Portsmouth (England),
University of Glasgow (Scotland),
University of Greifswald (Germany),
University of Rostock (Germany),
University of Cologne (Germany),
Max-Planck Institute for Gravitational Physics, Golm (Germany),
Kharkov Institute of Physics and Technology (Ukraine),
Bogolyubov Institute for Theoretical Physics, Kiev (Ukraine),
Bogolyubov Laboratory for Theoretical Physics, Dubna (Russia),
University of Napoli (Italy),
Jan Pawel II Catholic University of Lublin (Poland),
Copernicus Center for Interdisciplinary Studies, Kraków (Poland).