Brooks, W., & William Brooks. (2008). Perfect phrases for lead generation: Hundreds of ready-to-use phrases for finding new customers, keeping your pipeline full, and growing your sales. New York: McGraw-Hill.

Brooks, William, và William Brooks. Perfect Phrases for Lead Generation: Hundreds of Ready-to-use Phrases for Finding New Customers, Keeping Your Pipeline Full, and Growing Your Sales. New York: McGraw-Hill, 2008.

Brooks, William, và William Brooks. Perfect Phrases for Lead Generation: Hundreds of Ready-to-use Phrases for Finding New Customers, Keeping Your Pipeline Full, and Growing Your Sales. New York: McGraw-Hill, 2008.