1. Department of Experimental Physics, Faculty of Mathematics, Physics and Informatics; Comenius University in Bratislava; Bratislava Slovakia
2. J. Heyrovský Institute of Physical Chemistry; Academy of Sciences of the Czech Republic; Prague Czech Republic
3. Department of Astronomy, Physics of the Earth and Meteorology, Faculty of Mathematics, Physics and Informatics; Comenius University in Bratislava; Bratislava Slovakia