@misc {MATHEDUC.02401721,
    author       = {Stein, M.},
    title        = {How do pupils prove who did not have any lesson on proving. Wie begruenden Schueler, die noch keinen Unterricht im Beweisen hatten.},
    howpublished = {Math. Sch. (Nov 1992) v. 30(11) p. 622-626. CODEN: MKSCAS [ISSN 0465-3750]},
    year         = {1992},
    msc2010      = {E53xx (D43xx)},
    identifier   = {1993b.01889},
}