K. Haba, T. Izumi, Y. Katayama, N. Inuzuka, and K. Wada, On gathering problem in a ring for 2n autonomous mobile robots, 10th International Symposium on Stabilization, Safety, and Security of Distributed Systems (SSS), poster, 2008.

R. Klasing, A. Kosowski, and A. Navarra, Taking advantage of symmetries: Gathering of many asynchronous oblivious robots on a ring, Theoretical Computer Science, vol.411, issue.34-36, pp.411-3235, 2010.
DOI : 10.1016/j.tcs.2010.05.020
URL : https://hal.archives-ouvertes.fr/hal-00519069

R. Klasing, E. Markou, and A. Pelc, Gathering asynchronous oblivious mobile robots in a ring, Theoretical Computer Science, vol.390, issue.1, pp.27-39, 2008.
DOI : 10.1016/j.tcs.2007.09.032
URL : https://hal.archives-ouvertes.fr/hal-00307234

M. Koren, Gathering small number of mobile asynchronous robots on ring. Zeszyty Naukowe Wydzialu ETI Politechniki Gdanskiej, Technologie Informacyjne, vol.18, pp.325-331, 2010.

P. Flocchini, G. Prencipe, N. Santoro, and P. Widmayer, Gathering of asynchronous robots with limited visibility, Theoretical Computer Science, vol.337, issue.1-3, pp.147-168, 2005.
DOI : 10.1016/j.tcs.2005.01.001

T. Izumi, T. Izumi, S. Kamei, and F. Ooshita, Randomized Gathering of Mobile Robots with Local-Multiplicity Detection, 11th International Symposium on Stabilization, Safety, and Security of Distributed Systems (SSS), pp.384-398, 2009.
DOI : 10.1007/978-3-642-05118-0_27

T. Izumi, T. Izumi, S. Kamei, and F. Ooshita, Mobile Robots Gathering Algorithm with Local Weak Multiplicity in Rings, 17th International Colloquium on Structural Information and Communication Complexity (SIROCCO, pp.101-113, 2010.
DOI : 10.1007/978-3-642-13284-1_9

G. Prencipe, Impossibility of gathering by a set of autonomous mobile robots, Theoretical Computer Science, vol.384, issue.2-3, pp.222-231, 2007.
DOI : 10.1016/j.tcs.2007.04.023

D. Angelo, G. , D. Stefano, G. Navarra, and A. , Gathering of six robots on anonymous symmetric rings, Dipartimento di Ingegneria Elettrica e dell'Informazione, 2011.
URL : https://hal.archives-ouvertes.fr/hal-00644039