Yale University astronomer Debra Fischer says non-professional astronomers around the world are helping study the new information about the possible planets.

VOA: special.2011.02.09

Yale University is a non-profit corporation; the price of a share in Yale University is undefined-- it's zero over zero.

耶鲁大学可以看作是个非盈利组织,它的股价无法定义,是零除以零

耶鲁公开课 - 金融市场课程节选