| APA | Smart Define. (2016). extinct thesaurus. Retrieved September 21, 2026, from https://smartdefine.org/extinct/thesaurus/antonyms |
| Chicago | Smart Define. 2016. "extinct thesaurus" https://smartdefine.org/extinct/thesaurus/antonyms (accessed September 21, 2026). |
| Harvard | Smart Define 2016, extinct thesaurus, Smart Define, viewed 21 September, 2026, <https://smartdefine.org/extinct/thesaurus/antonyms>. |
| MLA | Smart Define. "extinct thesaurus" 10 February 2016. Web. 21 September 2026. <https://smartdefine.org/extinct/thesaurus/antonyms> |