Philip L. Bewig

Essential reading

Once information is loaded into a spreadsheet, it acquires properties that it may not deserve – a process called reification.
Incorrect use of Excel's NPV function is a common source of spreadsheet errors. We show several pitfalls and ways to avoid them.
Spreadsheets have errors like dogs have fleas. Nine out of every ten spreadsheets suffer some error, and consequences can be severe.
"Oh My God" my formulas are not working! This article covers most of the reasons for Excel formulas not working. And how to fix them.
Overconfidence is one of the main causes of spreadsheet errors. Being informed about overconfidence leads to more accurate spreadsheets.
Every study that has looked for errors has found them in considerable numbers. Spreadsheeting's childhood is over.
This article walks you through different methods and built-in tools that can be used to audit and debug Excel spreadsheets.
95% of all spreadsheets contain errors. So, it is almost certain that your spreadsheets are wrong.