@article{JGG_2005_9_2_JGG_2005_9_2_a0,
     author = {Z. Cerin},
     title = {Geometry of {Regular} {Heptagons}},
     journal = {Journal for geometry and graphics},
     pages = {119--132},
     year = {2005},
     volume = {9},
     number = {2},
     url = {http://geodesic.mathdoc.fr/item/JGG_2005_9_2_JGG_2005_9_2_a0/}
}