Cannot identify data for drop down list

[CassieL950]

I have a spreadsheet which was created by a predecessor (so I cannot ask them), it has multiple drop down menus, but no tab with data lists to show where these are pulled from, that I can see of. I need to edit the drop down menus to include some more options, it looks like a lookup is in place. The formula is =Lookups!$A$3:$A$17 . How do I go about editing this to allow further drop list options?  

[#2]

@CassieL950 

First of all, that formula gives the impression that there must be a tab called "Lookups"--which may well be a hidden tab. So you can try using "Format....Sheet....Unhide" to see if you can find it.

That aside, you could simple change the Data Validation source to one of your own making, put all the extant values into it and whatever new ones you wish to add.

Personally, I usually create a tab that is called "Tables" or something to that effect, and put it at the end of the other sheets in a workbook, but keep it available and visible. I'd recommend that once you've unhidden this particular source tab, that you keep it visible and, thereby, maintainable.