teaching aids 66 mathematics 34 management 33 civil engineering 31 steel structures 28 history 27 geodesy 25 more ... building constructions 24 controlling 23 examples 21 strength 20 transport 19 mathematical analysis 19 mathematical statistics 19 elasticity 19 agriculture 19 differential calculus 18 geometry 18 enterprise 18 probability theory 18 concrete constructions 17 physics 17 construction 17 architecture 16 economy 16 information systems 16 integral calculus 16 material engineering 16 telecommunications 16 electrotechnics 15 less ...