International Federation of Dental Hygienists, 30 Sep 2018 https://bmcoralhealth.biomedcentral.com/articles/10.1186/s12903-018-0623-2
International Dental Hygiene Educators' Forum, 30 Sep 2018 https://bmcoralhealth.biomedcentral.com/articles/10.1186/s12903-018-0623-2