J. K. Doyle

Mean distance for shapes

J. K. Doyle, J. E. Graver, J. Graver, 1982, J. Graph Theory.

Mean distance in a graph

J. K. Doyle, J. E. Graver, J. Graver, 1977, Discret. Math..

Mean Distance in a Directed Graph

Jack E. Graver, J. K. Doyle, 1978 .