| APA | Smart Define. (2013). harden the heart thesaurus. Retrieved October 1, 2026, from https://smartdefine.org/harden_the_heart/thesaurus/related |
| Chicago | Smart Define. 2013. "harden the heart thesaurus" https://smartdefine.org/harden_the_heart/thesaurus/related (accessed October 1, 2026). |
| Harvard | Smart Define 2013, harden the heart thesaurus, Smart Define, viewed 1 October, 2026, <https://smartdefine.org/harden_the_heart/thesaurus/related>. |
| MLA | Smart Define. "harden the heart thesaurus" 19 May 2013. Web. 1 October 2026. <https://smartdefine.org/harden_the_heart/thesaurus/related> |