1. Line graphs, root systems, and elliptic geometry;Cameron;J. Algebra,1976
2. Spectra of Graphs;Cvetković,1980
3. Generalized line graphs;Cvetković;J. Graph Theory,1981
4. Graphs and their spectra;Cvetković,1971
5. A geometric interpretation of the least eigenvalue of a line graph;Doob,1970