clusters
E Jonckheere, S G Schirmer, F C Langbein. Geometry and Curvature of Spin Networks. IEEE International Conference on Control Applicatons, pp. 786-791, 2011. [DOI:10.1109/CCA.2011.6044395] [arXiv:1102.3208] [PDF]

Geometry and Curvature of Spin Networks