1. Coppola, C., Pacelli, T.: Interval semimetric spaces for approximate distances. In: Proceedings of the 2005 Conference of the European Society for Fuzzy Logic and Technology, EUSFLAT 2015, pp. 1263–1268 (2015)
2. Coppola, C., Pacelli, T.: Approximate distances, pointless geometry, and incomplete information. Fuzzy Sets Syst. 157, 2371–2383 (2006)
3. Gerla, G.: Poinless metric spaces. J. Symb. Logic 55, 207–219 (1990)
4. Gerla, G.: Pointless geometries. In: Bueckenhout, F. (ed.) Handbook of Incidence Geometry, pp. 1015–1031. Elsevier, Amsterdam (1994)
5. Di Cosmo, R., Miller, D.: Linear logic. In: Zalta, E.N. (ed.) The Stanford Encyclopedia of Philosophy. Spring (2016).
http://plato.stanford.edu/archives/spr2016/entries/logic-linear/