| APA | Smart Define. (1970). relative age of black holes thesaurus. Retrieved September 26, 2026, from https://smartdefine.org/relative_age_of_black_holes/thesaurus/broader |
| Chicago | Smart Define. 1970. "relative age of black holes thesaurus" https://smartdefine.org/relative_age_of_black_holes/thesaurus/broader (accessed September 26, 2026). |
| Harvard | Smart Define 1970, relative age of black holes thesaurus, Smart Define, viewed 26 September, 2026, <https://smartdefine.org/relative_age_of_black_holes/thesaurus/broader>. |
| MLA | Smart Define. "relative age of black holes thesaurus" 1 January 1970. Web. 26 September 2026. <https://smartdefine.org/relative_age_of_black_holes/thesaurus/broader> |