| APA | Smart Define. (2015). air letter thesaurus. Retrieved September 30, 2026, from https://smartdefine.org/air_letter/thesaurus/synonyms |
| Chicago | Smart Define. 2015. "air letter thesaurus" https://smartdefine.org/air_letter/thesaurus/synonyms (accessed September 30, 2026). |
| Harvard | Smart Define 2015, air letter thesaurus, Smart Define, viewed 30 September, 2026, <https://smartdefine.org/air_letter/thesaurus/synonyms>. |
| MLA | Smart Define. "air letter thesaurus" 14 April 2015. Web. 30 September 2026. <https://smartdefine.org/air_letter/thesaurus/synonyms> |