Ana Belén Barragáns-Martínez Jorge García Duque José J. Pazos Arias Ana Fernández Vilas Rebeca P. Díaz Redondo Requirements Specifications Evolution in a Multi-Perspective Environment. 39-46 2002 conf/compsac/2002 COMPSAC http://doi.ieeecomputersociety.org/10.1109/CMPSAC.2002.1044531 db/conf/compsac/compsac2002.html#Barragans-MartinezGPFD02