| APA | Smart Define. (2013). cost-efficient thesaurus. Retrieved September 21, 2026, from https://smartdefine.org/cost-efficient/thesaurus/antonyms |
| Chicago | Smart Define. 2013. "cost-efficient thesaurus" https://smartdefine.org/cost-efficient/thesaurus/antonyms (accessed September 21, 2026). |
| Harvard | Smart Define 2013, cost-efficient thesaurus, Smart Define, viewed 21 September, 2026, <https://smartdefine.org/cost-efficient/thesaurus/antonyms>. |
| MLA | Smart Define. "cost-efficient thesaurus" 27 June 2013. Web. 21 September 2026. <https://smartdefine.org/cost-efficient/thesaurus/antonyms> |