BLÁZSIK, Zoltán L., HÉGER, Tamás and SZŐNYI, Tamás, 2020, On the upper chromatic number and multiple blocking sets of PG(n,q). Journal of combinatorial designs [online]. 2020. Vol. 25, no. 2, p. 118–140. [Accessed 12 April 2025]. DOI 10.1002/jcd.21686. Retrieved from: https://onlinelibrary.wiley.com/doi/full/10.1002/jcd.21686