Variable to store name of sheet

So I have about 60 rows of data on a sheet titled November that I use to populate a pivot table. Long story short, the way I have it set up is that every month, I create a new 60 rows that reference values on a new sheet representing a new month. The problem that I've run into is figuring out a way to automate the way I reference the new sheet representing the new month. For example, I have a function: =SUMIF(November!N:N, "Gas",November!K:K). What I was thinking was setting it up to where the "November" part of the function is a variable that is defined in one cell. So instead of going through each of the 60 rows and changing the "November" part to it into whatever the name of the new sheet is, I change the value of one cell, which all 60 rows reference, which would allow me to save a ton of time in the future. Is there a way of doing that?