Hi
Been struggling with this for ages, I can get the two elements of this formula to work separately but not together - I hope the below makes sense! 
I am trying to get a formula to:
A) Search a column on another sheet to see if a reference number is present
The below works but gives me the total count
=COUNTIF({SHEET1}, REFERENCE1)
Return a result based on if a tick box is unchecked for the above confirmed reference
There would only be one unchecked entry on the other sheet of the reference number and loads with it checked, I only need to confirm if the reference is present and the tickbox is unchecked on that line.
Hope you can help, thanks