| APA | Smart Define. (1970). vaccination against diphtheria thesaurus. Retrieved September 28, 2026, from https://smartdefine.org/vaccination_against_diphtheria/thesaurus/broader |
| Chicago | Smart Define. 1970. "vaccination against diphtheria thesaurus" https://smartdefine.org/vaccination_against_diphtheria/thesaurus/broader (accessed September 28, 2026). |
| Harvard | Smart Define 1970, vaccination against diphtheria thesaurus, Smart Define, viewed 28 September, 2026, <https://smartdefine.org/vaccination_against_diphtheria/thesaurus/broader>. |
| MLA | Smart Define. "vaccination against diphtheria thesaurus" 1 January 1970. Web. 28 September 2026. <https://smartdefine.org/vaccination_against_diphtheria/thesaurus/broader> |