| APA | Smart Define. (2015). space travel thesaurus. Retrieved September 27, 2026, from https://smartdefine.org/space_travel/thesaurus/broader |
| Chicago | Smart Define. 2015. "space travel thesaurus" https://smartdefine.org/space_travel/thesaurus/broader (accessed September 27, 2026). |
| Harvard | Smart Define 2015, space travel thesaurus, Smart Define, viewed 27 September, 2026, <https://smartdefine.org/space_travel/thesaurus/broader>. |
| MLA | Smart Define. "space travel thesaurus" 14 April 2015. Web. 27 September 2026. <https://smartdefine.org/space_travel/thesaurus/broader> |