However, there is no unified theory on the second problem, whose related research has been scattered in all kinds of literatures across different fields.

而第二个问题却并不像前者那样存在统一的理论，对其研究则广泛散布于各类文献中。

youdao

However, there is no unified theory on the second problem, whose related research has been scattered in all kinds of literatures across different fields.

而第二个问题却并不像前者那样存在统一的理论，对其研究则广泛散布于各类文献中。

youdao