During the maintenance of this bibliography, comments and suggestions of many people were very helpful. In particular, we thank F. Aicardi, N. Askitas, G. Kuperberg, V. Liskovets, J.-B. Meilhan, D. Moskovich, K. Selwat, T. Stanford, A. Stoimenow, D. P. Thurston, A. Vaintrob, and S. Willerton.