Elements, American. "Ytterbium Fluoride". American Elements. Retrieved 2020-11-02. https://www.americanelements.com/ytterbium-fluoride-13760-80-0 ↩
"Dental Composite Fillers : High Radiopacity Ytterbium Fluoride". www.sukgyung.com. Retrieved 2020-11-02. http://www.sukgyung.com/1bio.php ↩