TED Talks
Ted: Ted Ed: Yttrium: Periodic Table Videos
The team at Periodicvideos has created a TED-Ed Lesson for every element of the periodic table. This one is about yttrium. It is found in moon rocks and bullet-proof glass. Come with us to Sweden to discover it.
Chemicool
Chemicool: Yttrium
Chemicool yields loads of information on the element. Everything from price to natural abundance.
Web Elements
Web Elements Periodic Table: Yttrium
At this site from Mark Winter at WebElement, you can navigate around for charts and graphs of data on Yttrium. Probably the most comprehensive of all periodic tables on the web.