| APA | Smart Define. (2015). portcullis thesaurus. Retrieved September 27, 2026, from https://smartdefine.org/portcullis/thesaurus/synonyms |
| Chicago | Smart Define. 2015. "portcullis thesaurus" https://smartdefine.org/portcullis/thesaurus/synonyms (accessed September 27, 2026). |
| Harvard | Smart Define 2015, portcullis thesaurus, Smart Define, viewed 27 September, 2026, <https://smartdefine.org/portcullis/thesaurus/synonyms>. |
| MLA | Smart Define. "portcullis thesaurus" 10 April 2015. Web. 27 September 2026. <https://smartdefine.org/portcullis/thesaurus/synonyms> |