| APA | Smart Define. (1970). ecologically-friendly thesaurus. Retrieved September 21, 2026, from https://smartdefine.org/ecologically-friendly/thesaurus/synonyms |
| Chicago | Smart Define. 1970. "ecologically-friendly thesaurus" https://smartdefine.org/ecologically-friendly/thesaurus/synonyms (accessed September 21, 2026). |
| Harvard | Smart Define 1970, ecologically-friendly thesaurus, Smart Define, viewed 21 September, 2026, <https://smartdefine.org/ecologically-friendly/thesaurus/synonyms>. |
| MLA | Smart Define. "ecologically-friendly thesaurus" 1 January 1970. Web. 21 September 2026. <https://smartdefine.org/ecologically-friendly/thesaurus/synonyms> |