found:Wikipedia, July 31, 2012(Yttrium is a chemical element with symbol Y and atomic number 39. It is a silvery-metallic transition metal chemically similar to the lanthanides and it has often been classified as a "rare earth element.")
found:Chemicool website, July 31, 2012:Yttrium element facts (Classification: Yttrium is a transition metal & rare earth)
LC Classification
QD181.Y1 (General and inorganic chemistry) -- Assigner: DLC