Book excerpt: With sales of over 200 million albums, AC/DC is not just the biggest rock band in the world. It's a family business built by three brothers: George, Malcolm and Angus Young. And, as with any business, some people prospered while others got hurt along the way. 'The Youngs' is unlike any AC/DC book you've read before. Less a biography, more a critical appreciation, it tells the story of the trio through 11 classic songs and reveals some of the personal and creative secrets that went into their making.