This book provides an overview of variable universal life products in the US. It is designed as a continuing education textbook for financial planners and insurance brokers.The language is simple to read and it provides exercises in each chapter. A review of different life insurance products is in the first chapter.
If you are interested in VULs because you are considering purchasing one, this is an outstanding book to get for the money. It describes how the polices work in a way that is much clearer than what is provided in a prospectus.
Unfortunately, the book does not make recommendations on companies or what premiums are at various companies. For that sort of advice, a book like "New Life Insurance Investment Advisor" by Ben Baldwin might be of interest.