What is the author's style in Twilight in the Desert by Matthew Simmons?

Author Matthew Simmons is an investment banker from Houston, Texas, who specializes in the energy industry. Although not a technical expert, Simmons is an oil industry insider, who has access to information necessary to write this book. His leverage as an investment banker for the energy industry has also given him the opportunity to see firsthand many of the technical challenges and other issues facing Saudi Arabia's oil industry today. Although the primary sources for this book are the Society of Petroleum Engineers papers, Simmons also provides eyewitness accounts from his own experience, which adds credibility to his claims.