就统一条约的序文措词出现了争论。

The controversy has arisen over the text of the preamble to the unification treaty.

又通过序文和历史事实的对比研究得出，《唐陆宣公集》虽然是年羹尧的家刻本，校订者和刻工都是南方人，但却刻竣于陕西。

It is further proved, by comparison between its preface and historical records, that though Tang Lu Xuan Gong Ji, whose proof-reader and carver is south people, belongs to Nian Gengyao s collection.