@article{MO_2003_26_3_a0,
     author = {A. Pontryagina},
     title = {Foreword (or {Afterword)}},
     journal = {Matemati\v{c}eskoe obrazovanie},
     pages = {2--5},
     publisher = {mathdoc},
     volume = {26},
     number = {3},
     year = {2003},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MO_2003_26_3_a0/}
}