history 120 botany 62 physiology 57 agriculture 52 architecture 49 water courses 41 geodesy 36 more ... flóra 25 water courses regulation 23 systematic botany 22 air force 21 military aircrafts 20 hydrology 19 channels 19 railway transport 19 geology 18 water management 18 towns 17 geography 16 osobnosti 16 deposits mining 15 industry 15 museums 14 mathematics 13 measurement 13 ancient monuments 13 radiocommunications 13 inland water traffic 13 military history 13 architectural designs 12 less ...