| APA | Smart Define. (2014). upper-class thesaurus. Retrieved September 21, 2026, from https://smartdefine.org/upper-class/thesaurus/antonyms |
| Chicago | Smart Define. 2014. "upper-class thesaurus" https://smartdefine.org/upper-class/thesaurus/antonyms (accessed September 21, 2026). |
| Harvard | Smart Define 2014, upper-class thesaurus, Smart Define, viewed 21 September, 2026, <https://smartdefine.org/upper-class/thesaurus/antonyms>. |
| MLA | Smart Define. "upper-class thesaurus" 22 January 2014. Web. 21 September 2026. <https://smartdefine.org/upper-class/thesaurus/antonyms> |