book The Primes. The associated website and blog are also excellent.
I met Chris in 1997, when he began helping the World Bank's senior management team work better together. He was also critical to the design and implementation of the first Development Marketplace (though his role, along with that of Monika Weber-Fahr, was unfortunately omitted from this otherwise excellent HBR account.)
I can say from experience that the principles Chris describes in his book are effective; I have used them over the past fourteen years. They seem deceptively simple, but I can attest to their power if applied consistently.