@electronic{www.research.ibm.com,
   title       = {IBM Research Mathe-Rätsel}, 
   url         = {http://www.research.ibm.com/ponder/},
   biburl      = {https://puma.uni-kassel.de/url/17ed0a3979e4170e1d03f4c19ab242a2/hotho},
   keywords    = {ibm mathe rätsel},
   added-at    = {2007-11-15T08:50:09.000+0100},
   description = {},
   interhash   = {17ed0a3979e4170e1d03f4c19ab242a2}, 
   intrahash   = {17ed0a3979e4170e1d03f4c19ab242a2}
}