@article{ACIRM_2013__3_1_61_0,
     author = {Keller, Matthias},
     title = {An overview of curvature bounds and spectral theory of planar tessellations},
     journal = {Actes des rencontres du CIRM},
     pages = {61--68},
     publisher = {CIRM},
     volume = {3},
     number = {1},
     year = {2013},
     doi = {10.5802/acirm.55},
     zbl = {06938603},
     language = {en},
     url = {http://archive.numdam.org/articles/10.5802/acirm.55/}
}