Brouwer, A. E. "Chang Graphs." http://www.win.tue.nl/~aeb/graphs/Chang.html.Brouwer, A. E.; Cohen, A. M.; and Neumaier, A. Distance-Regular Graphs. New York: Springer-Verlag, pp. 105-106, 1989.Brouwer, A. E. and van Lint, J. H. "Strongly Regular Graphs and Partial Geometries." In Enumeration and Design: Papers from the conference on combinatorics held at the University of Waterloo, Waterloo, Ont., June 14-July 2, 1982 (Ed. D. M. Jackson and S. A. Vanstone). Toronto, Canada: Academic Press, pp. 85-122, 1984.Brualdi, R. and Ryser, H. J. Combinatorial Matrix Theory. New York: Cambridge University Press, p. 152, 1991.Chang, L.-C. "The Uniqueness and Non-Uniqueness of the Triangular Association Scheme." Sci. Record Peking Math. Soc.3, 604-613, 1959.Chang, L.-C. "Association Schemes of Partially Balanced Designs with Parameters , , , and ." Sci. Record Peking Math.4, 12-18, 1960.DistanceRegular.org. "Chang Graphs (3 Graphs)." https://www.math.mun.ca/distanceregular/graphs//chang.html.Godsil, C. and Royle, G. Algebraic Graph Theory. New York: Springer-Verlag, p. 259, 2001.Hoffman, A. J. "On the Uniqueness of the Triangular Association Scheme." Ann. Math. Stat.31, 492-497, 1960.van Dam, E. R. and Haemers, W. H. "Which Graphs Are Determined by Their Spectrum?" Lin. Algebra Appl.373, 139-162, 2003.
, one of them being the triangular graph of order 8. The other three such graphs are known as the Chang graphs, illustrated above. The Chang graphs are also cospectral with the triangular graph 
, all having graph spectrum 
, meaning none of the these is determined by spectrum. 
but are not distance-transitive. They are pancyclic. 
"Chang", n
] for 
, 2, 3. 
, 
, 
, and 
." Sci. Record Peking Math. 4, 12-18, 1960.DistanceRegular.org. "Chang Graphs (3 Graphs)."