keyword: Graph theory – 4 free books.
Michael R. Berthold et al. (editors)
Foundations of Software Science and Computation Structures: 22nd International Conference, FOSSACS 2019, Held as Part of the European Joint Conferences on Theory and Practice of Software, ETAPS 2019, Prague, Czech Republic, April 6–11, 2019, Proceedings
Mikołaj Bojańczyk and Alex Simpson, editors