Item from Mathematical Reviews (American Mathematical Society)--access
their stable url through the AMS database via an institutional library:
MR1990307 (2004e:05088) Roberts, Fred S. On balanced signed graphs and
consistent marked graphs. Ordinal and symbolic data analysis (Amherst,
MA, 1998), 12 pp. (electronic), Electron. Notes Discrete Math., 2,
Elsevier, Amsterdam, 1999. (Reviewer: Sandra L. Arlinghaus) 05C22