B.) The paper credited too many sources by renowned historians.
C.) The paper showed signs of bias and lacked proper citations.
D.) The historian taught history at a prestigious but small university.
E.) The historian regularly maintained personal historical blogs.
The fact that that historian's paper showed signs of bias and lacked proper citations was surely the factor that led his colleagues to deem the research that he conducted unreliable and, consequently, to reject his work.
As experts and authorities in their respective field, historians must be objective and impartial and they must avoid positioning themselves or letting personal opinions influence their accounts of the past, since, by doing so, they run the risk of distorting the truth. Likewise, when using information from other authors or other sources, it is imperative that they cite them properly, in order to acknowledge them and grant their readers the chance to review them (if they wish to do so). Proper citations are the trademark of a professional, competent and trustworthy historian.
John Adams
Benjamin Franklin
Thomas Jefferson
George Washington