Carles Sanchez, Debora Gil, Antoni Rosell, Albert Andaluz, & F. Javier Sanchez. (2013). "Segmentation of Tracheal Rings in Videobronchoscopy combining Geometry and Appearance " In Sebastiano Battiato and José Braz (Ed.), _Proceedings of the International Conference on Computer Vision Theory and Applications_ (Vol. 1, pp. 153–161). Portugal: SciTePress.