@inbook {3322, title = {On n-contractive Fuzzy Logics. First results}, booktitle = {Uncertainty and Intelligent Information Systems}, year = {2008}, pages = {. 433-445}, publisher = {World Scientific}, organization = {World Scientific}, author = {Francesc Esteva and Carles Noguera and Joan Gispert}, editor = {Bouchon et alt.} }