| APA | Smart Define. (1970). scientific study of the universe thesaurus. Retrieved September 28, 2026, from https://smartdefine.org/scientific_study_of_the_universe/thesaurus/narrower |
| Chicago | Smart Define. 1970. "scientific study of the universe thesaurus" https://smartdefine.org/scientific_study_of_the_universe/thesaurus/narrower (accessed September 28, 2026). |
| Harvard | Smart Define 1970, scientific study of the universe thesaurus, Smart Define, viewed 28 September, 2026, <https://smartdefine.org/scientific_study_of_the_universe/thesaurus/narrower>. |
| MLA | Smart Define. "scientific study of the universe thesaurus" 1 January 1970. Web. 28 September 2026. <https://smartdefine.org/scientific_study_of_the_universe/thesaurus/narrower> |