@congreso_internacional{551, author = {Francisco Herrera and Enrique Herrera-Viedma and Luis Martínez}, title = {The use of Linguistic Information in Operational Research}, year = {2001}, pages = {857-862}, month = {July 25-28th}, publisher = {Joint 9th IFSA World Congress and 20th NAFIPS International Conference}, address = {Vancouver (Canada)}, }