Vladimir P. Korzhik, Bojan Mohar. Minimal Obstructions for 1-Immersions and Hardness of 1-Planarity Testing. In Ioannis G. Tollis, Maurizio Patrignani, editors, Graph Drawing, 16th International Symposium, GD 2008, Heraklion, Crete, Greece, September 21-24, 2008. Revised Papers. Volume 5417 of Lecture Notes in Computer Science, pages 302-312, Springer, 2008. [doi]
Abstract is missing.