 @misc{ wiki:xxx,
   author = "Wikipedia",
   title = "Zeolite --- Wikipedia{,} The Free Encyclopedia",
   year = "2014",
   url = "http://en.wikipedia.org/w/index.php?title=Zeolite&oldid=630708642",
   note = "[Online; accessed 7-December-2014]"
 }
  @misc{ zeo:xxx,
   author = "Woodford,Chris",
   title = "Zeolites",
   year = "2014",
   url = "http://www.explainthatstuff.com/zeolites.html.",
   note = "[Online; accessed 7-December-2014]"
 }

 @misc{ zeo2:xxx,
   author = "Petránek, Jan",
   title = "Zeolity",
   year = "2014",
   url = "http://www.geology.cz/aplikace/encyklopedie/term.pl?zeolity",
   note = "[Online; accessed 7-December-2014]"
 }
 
  @misc{ zeo3:xxx,
   author = "Václav Vávra a Zdeněk Losos",
   title = "Tektosilikáty",
   year = "2014",
   url = "http://mineralogie.sci.muni.cz/kap_7_14_tektosil/kap7_14_tektosil.htm",
   note = "[Online; accessed 7-December-2014]"
 }
 
 
 
