Gene L. Andrusco 
Bridge Bidding [EPUB ebook] 
The 'Asking for points’ method using the strong 2- club, Gerber and Blackwood Conventions

There are virtually hundreds of ways to bid a hand in Bridge. Over the years, starting with experts such as Ely Culbertson, other experts have 'invented’ special bidding techniques such as the Stayman method, Blackwood, Gerber, and dozens of others.

However, there is one technique that has never been fully explained by anyone — that method is called the 'Asking for Points’ method.