Autor/-in: John Walkenbach

John Walkenbach, arguably the foremost authority on Excel, has written 50+ books, including the bestselling Excel Bible, Excel Formulas, and Excel Power Programming with VBA, as well as more than 300 articles for publications such as PC World, InfoWorld, and Windows. He created the award-winning Power Utility Pak, and provides Excel information and insight at www.spreadsheetpage.com.