| APA | Smart Define. (2015). open-heart surgery thesaurus. Retrieved September 26, 2026, from https://smartdefine.org/open-heart_surgery/thesaurus/narrower |
| Chicago | Smart Define. 2015. "open-heart surgery thesaurus" https://smartdefine.org/open-heart_surgery/thesaurus/narrower (accessed September 26, 2026). |
| Harvard | Smart Define 2015, open-heart surgery thesaurus, Smart Define, viewed 26 September, 2026, <https://smartdefine.org/open-heart_surgery/thesaurus/narrower>. |
| MLA | Smart Define. "open-heart surgery thesaurus" 14 April 2015. Web. 26 September 2026. <https://smartdefine.org/open-heart_surgery/thesaurus/narrower> |