E. Cuvelier, and M. Aufaure. Proceedings of the 19th International Conference on Conceptual Structures (ICCS 2011), volume 6828 of Lecture Notes in Computer Science, page 91-103. Springer, (2011)
M. Eisermann. (2006)cite arxiv:math/0612459
Comment: 46 pages, 2 figures. v2: A few remarks have been added and numerous
misprints corrected. v3: Some applications (e.g. to link quandles) have been
added.
B. Kalpana, R. Nadarajan, and J. Babu. Compute '08: Proceedings of the 1st Bangalore annual Compute conference, page 1--6. New York, NY, USA, ACM, (2008)