@misc {MATHEDUC.02414071,
    author       = {Schuch, B.},
    title        = {Why so many mistakes with fractions. What do studies (research) on frations say. Warum so viele Fehler beim Bruchrechnen. Was sagen empirische Untersuchungen dazu.},
    howpublished = {Lehrer J. Hauptschulmag. (Nov 1989) v. 4(11) p. 13-16. [ISSN 0930-6951]},
    year         = {1989},
    msc2010      = {F43xx (D73xx)},
    identifier   = {1989l.00957},
}