By used books. They have the same words as the new ones. Also libraries.

"The past is a foreign country; they do things differently there."

P与NP问题是计算机科学中最重要的一个问题之一。

Investing is not about beating others at their game. It's about controlling yourself at your own game.

量子计算的未来取决于我们克服噪声和退相干挑战的能力。

You'll never be able to please everybody, so you might as well be yourself.