1. Shelekhov, A.M., Lazareva, V. B., Utkin, A. A. Curvilinear Three-Webs (Tver, 2013) [in Russian].
2. Blaschke, W. Einführung in die Geometrie der Waben (Birkhäuser-Verlag, 1955).
3. Lazareva, V. B., Shelekhov, A. M. “On Triangulations of the Plane by Pencils of Conics”, Matem. sb. 198, No. 11, 107–134 (2007).
4. Pottmann, H., Shi, L., Skopenkov, M. Darboux Cyclides andWebs From Circles (King Abdullah University of Science and Technology (KAUST), Saudi Arabia).