@article{MO_2006_1_a4,
     author = {A. Ustilovskaya},
     title = {Principles of {Thinking} and {Activities} {Theory} {Applied} to a {School} {Course} of {Geometry}},
     journal = {Matemati\v{c}eskoe obrazovanie},
     pages = {69--79},
     year = {2006},
     number = {1},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MO_2006_1_a4/}
}