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