If you're unfamiliar with Amazon's free Author Central tool or don't know how it works, don't worry; I'm here to break it down and make it easy for you to get up and running. (bookcovercafe.com)
The central tools of speculative analysis focus on the observable prices, trading volume, sentiment, and other objects that emerge as the expression of investor psychology. (hussmanfunds.com)
Their central tool was cryptography, the same idea that allows you to safely send your credit card number over the Internet via encrypted numbers. (discovermagazine.com)