history 132 architecture 70 botany 65 physiology 57 agriculture 52 water courses 46 geodesy 36 more ... flóra 27 water courses regulation 25 air force 24 systematic botany 23 channels 22 military aircrafts 21 railway transport 21 geology 20 hydrology 19 osobnosti 19 geography 18 towns 18 water management 18 ancient monuments 17 civil engineering 17 industry 16 inland water traffic 16 deposits mining 15 museums 15 dwelling houses 15 mathematics 14 water structures 14 architectural designs 13 less ...