It is difficult to not find a causal relationship.

发现不出这样的因果关系是很困难的。

youdao

But there is little academically accepted evidence of a causal relationship.

但是，没有理论能够证明二者之间的因果关系。

youdao

The book traced a causal relationship between the rate of monetary growth and the price level.

这本书细致地描绘了货币供应变化和通胀的水平因果关系。

youdao

The study does not explain the connection or show a causal relationship, he said.

CNN: Experts ponder link between creativity, mood disorders

But there is little academically accepted evidence of a causal relationship.

ECONOMIST: Schumpeter

Tobacco has been around longer than the United States, and a causal relationship between smoking and cancer has been acknowledged by the U.S. government for over three decades.

CNN: A brief history of tobacco