1. Research Institute of Agriculture Engineering, p. r. i., 161 01 Prague, Czech Republic
2. Department of Horticultural Machinery, Faculty of Horticulture, Mendel University in Brno, Valtická 337, 691 44 Lednice, Czech Republic
3. Institute of Technology, Hungarian University of Agriculture and Life Sciences, Páter Károly Utca 1, 2100 Gödöllő, Hungary
4. Department of Agricultural Engineering and Safety, Faculty of Engineering, Agriculture Academy, Vytautas Magnus University, LT-53362 Kaunas, Lithuania