[1] G. Chartrand L. Eroh R. Rashidi M. Schultz, and N. A. Sherwani:
Distance, stratified graphs, and greatest stratified subgraphs. Congress. Numer. 107(1995), 81-96.
MR 1369256
[2] G. Chartrand L. Holley R. Rashidi, and N. A. Sherwani: Distance in stratified graphs. Preprint.
[3] R. Rashidi:
The Theory and Applications of Stratified Graphs. Ph. D. Dissertation, Western Michigan University (1994).
MR 2692329