And then there was a non-overlapping, a 13-month period, where you didn't beat the market.

FORBES: Intelligent Investing

Mr Gould calls his thesis the principle of non-overlapping magisteria.

ECONOMIST: Religion and science

There are more than 1.4 million registered non-profits in the U.S., many with overlapping missions.

FORBES: How to Grow Your Non-Profit: A Quick Case Study