@misc {MATHEDUC.02450449,
    author       = {Lind, D.},
    title        = {The role of transparent paper in the treatment of congruent mappings. Zur Rolle von Transparentpapier bei der Behandlung von Kongruenzabbildungen.},
    howpublished = {Mathematikunterricht. (Apr 1978) v. 24(2) p. 60-75. [ISSN 0025-5807]},
    year         = {1978},
    identifier   = {1978d.01966},
}