author = { Hasemann, Klaus AND Hefendehl-Hebeker, Lisa AND Walther, Gerd },

title = { Vorwort der Herausgeber },

publisher = {Springer Science and Business Media LLC},

isbn = {0173-5322},

keywords = { Education , General Mathematics },

year = {2001},

url = { http://slubdd.de/katalog?TN_libero_mab2 }