| APA | Smart Define. (2016). efficiency thesaurus. Retrieved September 20, 2026, from https://smartdefine.org/efficiency/thesaurus/antonyms |
| Chicago | Smart Define. 2016. "efficiency thesaurus" https://smartdefine.org/efficiency/thesaurus/antonyms (accessed September 20, 2026). |
| Harvard | Smart Define 2016, efficiency thesaurus, Smart Define, viewed 20 September, 2026, <https://smartdefine.org/efficiency/thesaurus/antonyms>. |
| MLA | Smart Define. "efficiency thesaurus" 25 February 2016. Web. 20 September 2026. <https://smartdefine.org/efficiency/thesaurus/antonyms> |