@article{MEM_2010_39_1_a41,
     author = {{\CYRK}{\cyra}{\cyrc}{\cyra}{\cyrr}{\cyrs}{\cyrk}{\cyra}, {\CYRM}{\cyra}{\cyrr}{\cyrya}{\cyrn}{\cyra} and {\CYRT}{\cyro}{\cyrd}{\cyro}{\cyrr}{\cyro}{\cyrv}{\cyra}, {\CYRM}{\cyra}{\cyrr}{\cyrg}{\cyra}{\cyrr}{\cyri}{\cyrt}{\cyra}},
     title = {{\CYRI}{\cyrg}{\cyrr}{\cyra}{\cyrt}{\cyra} {\cyrv} {\cyro}{\cyrb}{\cyru}{\cyrch}{\cyre}{\cyrn}{\cyri}{\cyre}{\cyrt}{\cyro} {\cyrp}{\cyro} {\cyrm}{\cyra}{\cyrt}{\cyre}{\cyrm}{\cyra}{\cyrt}{\cyri}{\cyrk}{\cyra} {\cyrv} {\cyrp}{\cyre}{\cyrt}{\cyri} {\cyrk}{\cyrl}{\cyra}{\cyrs}},
     journal = {Mathematics and Education in Mathematics},
     pages = {340--346},
     publisher = {mathdoc},
     volume = {39},
     number = {1},
     year = {2010},
     language = {bg},
     url = {http://geodesic.mathdoc.fr/item/MEM_2010_39_1_a41/}
}