ingi+(H)sources


 * SOURCES**

1) http://www.webelements.com/webelements/elements/text/Pb/key.html

2) http://education.jlab.org/itselemental/ele082.html

3) http://www.radiochemistry.org/periodictable/elements/82.html

4) http://www.infoplease.com/ce6/sci/A0829134.html