Semantic Closure: A Guiding Notion to Ground Artificial Life. - Jon Umerez (ECAL, 1995)

Organizational requirements for 'open-ended evolution'. - Kepa Ruiz-Mirazo; Jon Umerez; Alvaro Moreno (ALIFE, 2008)

Conceptual Issues in Evolutionary Biology (3rd ed.). Elliott Sober (Ed.). (2006, Cambridge MA: MIT Press.) 640 pages. - Arantza Etxeberria; Jon Umerez (Artif. Life, 2008)

The autonomy of biological individuals and artificial models. - Alvaro Moreno; Arantza Etxeberria; Jon Umerez (Biosyst., 2008)