| APA | Smart Define. (2011). crab nebula thesaurus. Retrieved September 23, 2026, from https://smartdefine.org/crab_nebula/thesaurus/broader |
| Chicago | Smart Define. 2011. "crab nebula thesaurus" https://smartdefine.org/crab_nebula/thesaurus/broader (accessed September 23, 2026). |
| Harvard | Smart Define 2011, crab nebula thesaurus, Smart Define, viewed 23 September, 2026, <https://smartdefine.org/crab_nebula/thesaurus/broader>. |
| MLA | Smart Define. "crab nebula thesaurus" 26 April 2011. Web. 23 September 2026. <https://smartdefine.org/crab_nebula/thesaurus/broader> |