Ruback, Richard and Royce Yudkoff. February 16, 2016. "HBR Guide to Buying a Small Business.".
"Paperback and e-Book published by the developers of an HBS MBA Elective course on Financial Management of Small Firms and Entrepreneurship through Acquisition."

Brynes, Jonathan. 2010. Islands of Profit in a Sea of Red Ink. Penguin Group.
"Nearly 40 percent of the average revenues in a company is unprofitable, and 25% percent is so profitable that it provides all the earnings and subsidizes the losses."