Keywords: K6-Petersen duality.svg Petersen graph have dual embeddings on the projective plane 2015-08-13 Email David Wood other versions Custom license marker 2015 08 14 Cc-zero Per email from the author 2015-08-13 You have my permission to do anything you like with it under any license that you like Uploaded with UploadWizard Projective plane Petersen graph Complete graph K6 |