David H. Ringstrom David is a CPA and owner of Accounting Advisors, Inc., an Atlanta-based spreadsheet consulting firm that he started in 1991. David's first book will be published February 2016, and he has served as the technical editor for dozens of books on accounting software. In addition to teaching 180 live webinars per year, David also occasionally speaks at conferences on Microsoft Excel. He has written hundreds of articles on spreadsheets, some of which have been published internationally. David provides Microsoft Excel training and consulting services nationwide.