@conference{Fargier93a,
author = "D. Dubois and H. Fargier and H. Prade",
address = "San Francisco, CA",
booktitle = "Proc. 2$^nd$ IEEE Conference on Fuzzy Systems",
month = "mar",
title = "{T}he calculus of fuzzy restrictions as a basis for
                   flexible constraint satisfaction",
year = "1993",
}