00319nam a2200097Ia 4500008004100000020001800041100002800059245008700087260002800174300001900202180315s9999    xx            000 0 und d  a9780071592062  aChristensen, Clayton M.  aDisrupting class :bHow disruptive innovation will change the way the world learns  aUSA :b2008cmcGrawHill  aiii, 231 pages