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

My guess is they don't even really have a reference for what a chaplain is.

我想他们应该也不大了解,教士到底是干什么的吧。

普林斯顿公开课 - 人性课程节选

Ian Hacking, who wrote a history of probability theory, searched through world literature for any reference to a probability and could find none anywhere before 1600.

伊恩·哈金为概率论追根溯源,他查遍世界所有关于概率的文献,发现无法追溯到十七世纪以前

耶鲁公开课 - 金融市场课程节选

Now, when you starting looking for next week, you are going to see reference to a chapter, which is in the core text, and you will also see this LN, LN, LN archives.

现在，当你们开始为下礼拜阅读的时候，你们要看一章的参考资料，也就是核心文本，你们也要看这个LN档案。

麻省理工公开课 - 固态化学导论课程节选