@phdthesis{Vid96,
 author = {G. Vidal}, 
 title  = {Semantics-Based Analysis and Transformation of
           Functional Logic Programs},
 school = "Departamento de Sistemas Inform\'aticos y Computaci\'on,
           Universidad Polit\'ecnica de Valencia",
 month  = {Sept.},
 year   = 1996,
 note   = {In spanish}
}