R. Cole. 24th Australiasian Computer Science Conference, том 23 из Australian Computer Science Communications, стр. 47-53. IEEE Computer Society, (2001)more details of this in Cole's PhD thesis.
R. Cole. 23th Australiasian Computer Science Conference, том 22 из Australian Computer Science Communications, стр. 47-53. IEEE Computer Society, (2000)more details of this in Cole's PhD thesis.
P. Becker. Proceedings of the 9th International Conference on Conceptual Structures, стр. 33-46. Department of Computer Science, University Laval, (2001)