| APA | Smart Define. (2013). nonnecessity thesaurus. Retrieved September 23, 2026, from https://smartdefine.org/nonnecessity/thesaurus/antonyms |
| Chicago | Smart Define. 2013. "nonnecessity thesaurus" https://smartdefine.org/nonnecessity/thesaurus/antonyms (accessed September 23, 2026). |
| Harvard | Smart Define 2013, nonnecessity thesaurus, Smart Define, viewed 23 September, 2026, <https://smartdefine.org/nonnecessity/thesaurus/antonyms>. |
| MLA | Smart Define. "nonnecessity thesaurus" 28 June 2013. Web. 23 September 2026. <https://smartdefine.org/nonnecessity/thesaurus/antonyms> |