@inproceedings{cp-dcncb-17
, author = "Colin~de Verdi{\`e}re, {\'E}ric and Parsa, Salman"
, title = "Deciding contractibility of a non-simple curve on the
boundary of a 3-manifold"
, booktitle = "Proceedings of the 28th Annual ACM-SIAM Symposium on
Discrete Algorithms (SODA)"
, year = "2017"
, pages = "2691--2704"
}