@electronic{www.ptb.de,
   title       = {Physikalisch-Technische Bundesanstalt (PTB): Atomzeit online}, 
   url         = {http://www.ptb.de/de/zeit/uhrzeit.html},
   biburl      = {https://puma.uni-kassel.de/url/98a76dc0d99a2e242864c222172eb718/benz},
   keywords    = {atomuhr atomzeit internet online},
   added-at    = {2011-02-04T16:08:30.000+0100},
   description = {},
   interhash   = {98a76dc0d99a2e242864c222172eb718}, 
   intrahash   = {98a76dc0d99a2e242864c222172eb718}
}