joseph Glatthaar's Forged in Battle is not the first excellent study of Black soldiers and their White officers in the Civil War but it uses more soldier's letters and diaries---including rare material from Black soldiers---and concentrates more intensely on Blackk -White relations in Black regiments than do any of its predecessors.Glattaar's title expresses his theses：loyalty,friendship,and respect among White offiers and Black soldiers were fostered by the mutual dangers they faced in combat.
其中的expresses his theses 中的theses如何理解，意思是什么？是不是印刷错误？
