@misc {MATHEDUC.02416605,
    author       = {Helmke, A. and Schrader, F.W.},
    title        = {Successful student practice during seatwork: efficient management and active supervision not enough. Erfolgreiches Ueben in Stillarbeit: Effektives Management und aktive Aufsicht sind nicht genug.},
    howpublished = {J. Educ. Res. (Nov-Dec 1988) v. 82(2) p. 70-75. CODEN: JEDRAP [ISSN 0022-0671]},
    year         = {1988},
    msc2010      = {D43xx (C73xx)},
    identifier   = {1989f.00617},
}