The reference has not verified this book in detail; the summary states only what the title, author and subject establish.
This is a compilation volume marking fifty years of Berkshire Hathaway under Warren Buffett and Charlie Munger, assembled around the 2015 anniversary. The reference has not verified this particular edition's contents, its editor or its publisher.
What the title and occasion establish is that it collects material relating to the Buffett and Munger partnership at Berkshire from 1965 onward. The 2014 annual report, published in early 2015, contained the definitive fiftieth anniversary material: Buffett's essay on the past and future of Berkshire and Munger's separate essay on what he called the Berkshire system, which is the most direct statement either has made about why the company worked. That material is available without charge from Berkshire's own website.
Readers wanting the primary sources should use the annual letters, which Berkshire publishes free, and Cunningham's edited Essays of Warren Buffett, which organises the letters by topic. Lawrence Cunningham's Berkshire Beyond Buffett examines the subsidiaries and the culture. This compilation should be checked against those before being relied on, since the reference cannot confirm what it contains or who assembled it.
Readers should use Berkshire's own published letters and Cunningham's edited Essays instead, since this compilation's contents are unverified here.
Chosen by shared topics, the entries that hold them, and the people who recommended both.

