| APA | Smart Define. (2011). diurnal course thesaurus. Retrieved September 22, 2026, from https://smartdefine.org/diurnal_course/thesaurus/synonyms |
| Chicago | Smart Define. 2011. "diurnal course thesaurus" https://smartdefine.org/diurnal_course/thesaurus/synonyms (accessed September 22, 2026). |
| Harvard | Smart Define 2011, diurnal course thesaurus, Smart Define, viewed 22 September, 2026, <https://smartdefine.org/diurnal_course/thesaurus/synonyms>. |
| MLA | Smart Define. "diurnal course thesaurus" 21 May 2011. Web. 22 September 2026. <https://smartdefine.org/diurnal_course/thesaurus/synonyms> |