He has put forward principles behind tax reform that include the Buffett principle and reducing deductions that the wealthiest Americans can take.

WHITEHOUSE: Press Briefing by Press Secretary Jay Carney,

This principle of diversification works in increasing returns and in reducing risk.

FORBES: Expert View

Convinced that education plays a key role in reducing conflict, prejudice, poverty and intolerance around the world, his work is based on the guiding principle of providing access for all young people to better schooling.

UNESCO: Detailview | United Nations Educational, Scientific and Cultural Organization