<http://schema.org/dateModified>
"2015-07-22T07:54:02Z"^^<http://schema.org/Date>
<http://chemwiki.ucdavis.edu/Inorganic_Chemistry/Descriptive_Chemistry/Elements_Organized_by_Block/2_p-Block_Elements/Group_14%3A_The_Carbon_Family/Chemistry_of_Tin>