1999, Part of book or chapter of book (Flum, J.; Rodriguez Artalejo, M. (ed.), 13th International Workshop, CSL'99, 8th Annual Conference of the EACSL, Madrid, Spain, September 20-25, 1999, Proceedings, pp. 439-452)
1997, Part of book or chapter of book (Johnson, M. (ed.), Algebraic Methodology and Software Technology: 6th International Conference, AMAST'97 Sydney, Australia, December13–17, 1997 Proceedings, pp. 276-291)
1997, Part of book or chapter of book (Moggi, E.; Rosolini, G. (ed.), Category Theory and Computer Science: 7th International Conference, CTCS '97 Santa Margherita Ligure Italy, September 4–6, 1997 Proceedings, pp. 220-241)
1994, Part of book or chapter of book (Nerode, A.; Matiyasevich, Y.V. (ed.), Logical Foundations of Computer Science: Third International Symposium, LFCS '94 St. Petersburg, Russia, July 11–14, 1994 Proceedings, pp. 173-183)
1993, Part of book or chapter of book (Bezem, M. (ed.), Typed Lambda Calculi and Applications: International Conference on Typed Lambda Calculi and Applications TLCA '93 March, 16–18, 1993, Utrecht, The Netherlands. Proceedings, pp. 209-229)