Quickly linking cell values to other workbooks

The number in the file goes to zero when the other file that it’s getting the data from is not open. Is there any way around that? It’s strange because when I use

=’C:\Mike\My Documents\[Fuel Usage Year 1.xlsx]Sheet1’!$A$1
the summary file will keep that value when the other excel file is closed but when I use

=indirect(“’C:\Mike\My Documents\[Fuel Usage Year “&B1&”.xlsx]Sheet1’!$A$1”)
the cell turns to 0 when the base data file is closed!

So it has something to do with the =indirect(…) function but I need that to drag the cell down instead of typing 100 different file paths.

Any ideas?