@article{MEM_2010_39_1_a30,
     author = {{\CYRV}{\cyre}{\cyrl}{\cyri}{\cyrk}{\cyro}{\cyrv}{\cyra}, {\CYRE}{\cyrv}{\cyrg}{\cyre}{\cyrn}{\cyri}{\cyrya} and {\CYRG}{\cyrr}{\cyri}{\cyrg}{\cyro}{\cyrr}{\cyro}{\cyrv}{\cyra}, {\CYRD}{\cyre}{\cyrn}{\cyri}{\cyrc}{\cyra} and {\CYRS}{\cyrl}{\cyra}{\cyrv}{\cyrch}{\cyro}{\cyrv}{\cyra}-{\CYRB}{\cyro}{\cyrzh}{\cyrk}{\cyro}{\cyrv}{\cyra}, {\CYRM}{\cyra}{\cyrr}{\cyru}{\cyrs}{\cyri}{\cyrya}},
     title = {{\CYRA}{\cyrn}{\cyra}{\cyrl}{\cyri}{\cyrz} {\cyri} {\cyrv}{\cyrl}{\cyri}{\cyrya}{\cyrn}{\cyri}{\cyre} {\cyrn}{\cyra} {\cyrp}{\cyrr}{\cyri}{\cyre}{\cyrm}{\cyra} {\cyrs} {\cyrm}{\cyra}{\cyrt}{\cyru}{\cyrr}{\cyra} {\cyrv} {\cyrk}{\cyra}{\cyrn}{\cyrd}{\cyri}{\cyrd}{\cyra}{\cyrt}-{\cyrs}{\cyrt}{\cyru}{\cyrd}{\cyre}{\cyrn}{\cyrt}{\cyrs}{\cyrk}{\cyra}{\cyrt}{\cyra} {\cyrk}{\cyra}{\cyrm}{\cyrp}{\cyra}{\cyrn}{\cyri}{\cyrya} 2009 {\cyrv}{\cyrhrdsn}{\cyrv} {\cyrf}{\cyra}{\cyrk}{\cyru}{\cyrl}{\cyrt}{\cyre}{\cyrt}{\cyra} {\cyrp}{\cyro} {\cyrm}{\cyra}{\cyrt}{\cyre}{\cyrm}{\cyra}{\cyrt}{\cyri}{\cyrk}{\cyra} {\cyri} {\cyri}{\cyrn}{\cyrf}{\cyro}{\cyrr}{\cyrm}{\cyra}{\cyrt}{\cyri}{\cyrk}{\cyra} {\cyrn}{\cyra} {\cyrs}{\cyru} {\textquotedblleft}{\cyrs}{\cyrv}. {{\CYRK}{\cyrl}.} {{\CYRO}{\cyrh}{\cyrr}{\cyri}{\cyrd}{\cyrs}{\cyrk}{\cyri}{\textquotedblright}}},
     journal = {Mathematics and Education in Mathematics},
     pages = {268--273},
     publisher = {mathdoc},
     volume = {39},
     number = {1},
     year = {2010},
     language = {bg},
     url = {http://geodesic.mathdoc.fr/item/MEM_2010_39_1_a30/}
}