http://npt2000.homeip.net/hellebrant/tudasteszt_minta.ppt

http://npt2000.homeip.net/hellebrant/nevelestortenet_infok_2009_10.ppt

http://npt2000.homeip.net/hellebrant/Hellebrant1915_WJLF1ev.xls

http://npt2000.homeip.net/hellebrant/Hellebrant1907_WJLF1ev.xls

http://npt2000.homeip.net/hellebrant/1915MPR.pdf

http://npt2000.homeip.net/hellebrant/1907MPR.pdf