http://www.webelements.com/ruthenium/
http://www.chemicool.com/elements/ruthenium.html
http://www.infoplease.com/periodictable.php?id=44
http://www.ptable.com/#Property/State
http://www.chemicool.com/elements/ruthenium.html
http://www.infoplease.com/periodictable.php?id=44
http://www.ptable.com/#Property/State