|Hitti, History of the Arabs, 10th edition 1970 , p|
|5, "One major challenge to examining initial contacts between Byzantium and the early Muslim umma arises from the controversy surrounding the traditional Islamic account||Moreover, many of them provide evidence of embellishment and invention that were introduced to serve the purposes of political or religious apologetic|
|137 Netanel's work was virtually unknown beyond his native Yemen until modern times, so had little influence on later Jewish thought• Ideally, one would like to be able to check such accounts against contemporary evidence||"Muhmmad," Encyclopedia of Islam and the Muslim world• 597, which notes that many of the details surrounding Muhammad's life as given in the biographies, are "problematic in certain respects, the most important of which is that they represent a tradition of living narrative that is likely to have developed orally for a considerable period before it was given even a relatively fixed written form|
|Seeing Islam as others saw it: a survey and evaluation of Christian, Jewish, Robert G|
These sources contain internal complexities, anachronisms, discrepancies, and contradictions.