Source code for ooxml-schemas-1.1.jar

[Sivakumar Kaviyappa]

Hi,
  Can anybody please tell me how to get the source code for the classes in
 ooxml-schemas-1.1.jar  jar file , I am particularly interested in
org.openxmlformats.schemas.spreadsheetml.x2006.main.CTRPrElt;

 I am having an issue with this code,

 XSSFRichTextString richtextstring= cell.getRichStringCellValue();
          for(int i=0;i<richtextstring.length();i++){
               //Null Pointer Exception!!!
               //newFont=richtextstring.getFontAtIndex(i);
          }

Upon googling I found some posts saying the source code is
in ooxml-schemas-src-1.1.jar but I am not able to find in maven. I am sorry
I not a maven user..


Thanks,
Siva