1. Brouwer, A.E., van Maldeghem, H.: Strongly Regular Graphs, Encyclopedia Math. Appl. 182 (Cambridge University Press 2022), xvii+462 pp
2. Biggs, N.L.: Algebraic Graph Theory, 2nd edn. Cambridge University Press, Cambridge (1993), page 159
3. Brouwer, A.E., Cohen, A.M., Neumaier, A.: Distance-Regular Graphs, p. 434. Springer-Verlag, Berlin (1989)
4. Chernyak, Zh.A.: Some additions to an article by B. Manvel: "Some basic observations on Kelly’s conjecture for graphs” (Russian), Vestsī Akad. Navuk BSSR Ser. F$${\bar{i}}$$z.-Mat. Navuk 126, 44–49 (1982)
5. Dalfó, C., van Dam, E.R., Fiol, M.A., Garriga, E., Gorissen, B.L.: On almost distance-regular graphs. J. Combin. Theory Ser. A 118, 1094–1113 (2011)