@misc {IOPORT.70971315,
    author       = {Droujkova, Maria A. and Droujkov, Dmitri A.},
    title        = {Using XP with children for learning mathematics},
    howpublished = {XP, 418-419 (2003).},
    year         = {2003},
    doi          = {10.1007/3-540-44870-5_65},
    identifier   = {70971315},
}