1. NASA Office of Planetary Protection (2016). Planetary Protection History. https://planetaryprotection.nasa.gov/history
2. The Earth Charter Initiative (2000). The Earth Charter [PDF]. http://earthcharter.org/discover/download-the-charter
3. Geoética: un reto para la deontología professional;González;Tierra y tecnología,2011
4. Kminek G. & Rummel J. (2015). Space Research Today, COSPAR's information bulletin. COSPAR's Planetary Protection Policy (193). https://cosparhq.cnes.fr/sites/default/files/ppp_article_linked_to_ppp_webpage.pdf
5. International Group on Astrobioethics (2016). Working Group on Astrobioethics. http://www.icog.es/iageth/index.php/p3loki-gn/