| APA | Smart Define. (2013). impossible to solve thesaurus. Retrieved September 24, 2026, from https://smartdefine.org/impossible_to_solve/thesaurus/related |
| Chicago | Smart Define. 2013. "impossible to solve thesaurus" https://smartdefine.org/impossible_to_solve/thesaurus/related (accessed September 24, 2026). |
| Harvard | Smart Define 2013, impossible to solve thesaurus, Smart Define, viewed 24 September, 2026, <https://smartdefine.org/impossible_to_solve/thesaurus/related>. |
| MLA | Smart Define. "impossible to solve thesaurus" 19 May 2013. Web. 24 September 2026. <https://smartdefine.org/impossible_to_solve/thesaurus/related> |