Fairey says he used the AP photograph as a reference, but then changed it greatly for his own idealized and colorful picture of Barack Obama.

VOA: special.2009.04.08

The problems that Frost's poetry poses for us as readers are not problems of reference. They can't be solved by footnotes.

他的诗歌给我们的困难,不是参考的问题，它们不能就用脚注解决。

耶鲁公开课 - 现代诗歌课程节选

If you're an inertial observer, then in your system of reference, objects left at rest will remain at rest.

如果你是惯性观察者,那么在你的参考系内,静止的物体会保持静止

耶鲁公开课 - 基础物理课程节选

Editors' Note: The description of Bio-Reference has been revised to correct an erroneous reference to financiers of the company during its first 15 years.

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In the past week, 18% of the time that Ray Lewis is mentioned on social media, it is a negative reference, and of that negative conversation, approximately half of the mentions reference his involvement in the aforementioned Atlanta nightclub murder.

FORBES: Baltimore Ravens' Ray Lewis Still Questioned In The Court Of Public Opinion

There are tens of thousands of reference apps, covering every sphere of human knowledge.

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