@article {ekim2014polar, title = {Polar cographs}, journal = {Discrete Applied Mathematics}, volume = {171}, number = {EPFL-ARTICLE-199582}, year = {2014}, pages = {158{\textendash}158}, publisher = {Elsevier Science Bv}, author = {Ekim, Tinaz and Mahadev, NVR and de Werra, Dominique} }