Kevin Buchin Christian Knauer Klaus Kriegel André Schulz Raimund Seidel On the Number of Cycles in Planar Graphs. 97-107 2007 conf/cocoon/2007 COCOON http://dx.doi.org/10.1007/978-3-540-73545-8_12 db/conf/cocoon/cocoon2007.html#BuchinKKSS07