with Smith, B. J. , 2006, A framework for analyzing and testing requirements with actors in conceptual graphs, in P. Hitzler & P. Øhrstrøm (eds.), Conceptual structures: inspiration and application, Dordrecht, Springer, pp. 401-412.
with Harper, L. W. , 2004, Using conceptual graphs to represent agent semantic constituents, in K. E. Wolff, H. D. Pfeiffer & H. Delugach (eds.), Conceptual structures at work, Dordrecht, Springer, pp. 333-345.
with Wolff, K. , Pfeiffer, H. D. (eds) , 2004a, Conceptual structures at work: 12th international conference on conceptual structures, Springer, Dordrecht.