The material conditions of freedom is an updated version of an earlier book (published in 1999) called El derecho a la existencia (The right to existence). This is a comprehensive volume about Basic Income (BI), dealing in a detailed fashion its definition(s), related theory, discussions about work, welfare, BI financing and typical criticisms of BI. Although dated from 2007, the volume is now accessible online.
Daniel Raventós (trans. Julie Wark), The material conditions of freedom, Pluto Press, 2007