The Excel Function Bible is aimed at providing meaningful and practical help in finding and implementing 468 Excel functions. It replaces and adds significantly to the help users can call for whilst building or using Excel workbooks.
A fully inclusive set of indexes allows users to find particular functions and gives the brief descriptions. Using these indexes on the classifications web pages users can bring up individual files for each function.
The first worksheet of each function file provides descriptions of the functions, the syntax, and descriptions of the arguments required. The front page includes a brief history of the function that allows users to determine which versions of Excel introduced the function and whether and when capabilities of the functions were changed. Each front page provides details of any equations used by the function in traditional and linear format. An addition section provides the cause of error messages that may be returned by the function. There is also a link on this worksheet to the Excel online help for the function.
Second and subsequent worksheets provide copy and paste facilitated examples of the use of the function ranging from simple implementation to more complex examples of use including use by interaction with other functions.
You can read more about it here: Excel Function Bible