The division between Shia and Sunni Muslims originally arose over
Religion - PsyDAG, Tuesday, May 31, 2011 at 6:36pm
Indicate your subject in the "School Subject" box, so those with expertise in the area will respond to the question.
Since this is not my area of expertise, I searched Google under the key words "Shia vs. Sunni Muslims " to get these possible sources:
In the future, you can find the information you desire more quickly, if you use appropriate key words to do your own search. Also see http://hanlib.sou.edu/searchtools/.