I type of shape, or a pointing index finger
The predefined formulas in Excel that contain the Boolean functions fall under the Logical Functions category. The Boolean functions consist of "AND", "OR", "XOR", "NOT", "IF", "IFERROR" and "IFNA". When you need to use an Excel Function, you can type the function into the cell. You also need to add the arguments for the function in between brackets. If the function is complex or you are a beginner user, there is a function inputting tool which will help you choose which function you require.
Since you are searching for researching information, .edu will be more reliable.
.edu is for education purpose, with credits of scholars.
.com is a general URL, it's not relavant to reliability.