What is the author's style in Sam Walton, Made in America: My Story by Sam Walton?

The book is mainly written from the perspective of Sam Walton. However, one of the most interesting aspects of the book is the additional commentary that is sprinkled throughout the text. Sam will sometimes comment to the statements by his wife, associates or children, but more often, these statements help to provide another perspective to the story. These commentary pieces are a true enhancement to the book and make it far richer than if Sam had been the sole voice throughout. The main concentration of the novel, however, is shown through Sam Walton's eyes and his voice.