| APA | Smart Define. (2016). challenging thesaurus. Retrieved September 24, 2026, from https://smartdefine.org/challenging/thesaurus/related |
| Chicago | Smart Define. 2016. "challenging thesaurus" https://smartdefine.org/challenging/thesaurus/related (accessed September 24, 2026). |
| Harvard | Smart Define 2016, challenging thesaurus, Smart Define, viewed 24 September, 2026, <https://smartdefine.org/challenging/thesaurus/related>. |
| MLA | Smart Define. "challenging thesaurus" 2 March 2016. Web. 24 September 2026. <https://smartdefine.org/challenging/thesaurus/related> |