What matters in life is not what happens to you but what you remember and how you remember it.
Patience and persistence are the keys to unlocking the mysteries of mathematics.
I think the most important thing is to be honest with yourself and with others.
He who would search for pearls must dive below.
The coal industry has been the backbone of America's energy independence for generations.
"The only way to deal with an unfree world is to become so absolutely free that your very existence is an act of rebellion."