MS Excel Expert David H. Ringstrom is a certified public accountant and owner of Accounting Advisors, Inc., an Atlanta, Georgia-based spreadsheet consulting firm that he started in 1991. David speaks at conferences and presents webinars to thousands of attendees annually on Excel and other topics. He has written hundreds of freelance articles on spreadsheets, some of which have been published internationally. David's catch phrase is "Either you work Excel or it works you." His goal is to make you a smarter and more effective spreadsheet user.