| APA | Smart Define. (2013). extinction of life thesaurus. Retrieved September 29, 2026, from https://smartdefine.org/extinction_of_life/thesaurus/related |
| Chicago | Smart Define. 2013. "extinction of life thesaurus" https://smartdefine.org/extinction_of_life/thesaurus/related (accessed September 29, 2026). |
| Harvard | Smart Define 2013, extinction of life thesaurus, Smart Define, viewed 29 September, 2026, <https://smartdefine.org/extinction_of_life/thesaurus/related>. |
| MLA | Smart Define. "extinction of life thesaurus" 17 May 2013. Web. 29 September 2026. <https://smartdefine.org/extinction_of_life/thesaurus/related> |