Sumif Formula using Cell content to refer to sheetname

[Smithsat34]

Board,

I have a three worksheets in a workbook, each one contains a months worth of data. They are titled Aug 16, Sep 16 & Oct 16.
I have a single summary sheet with a few sumif formulas. Ideally I want to be able to change a single cell on my summary sheet to reflect which month the sumif should look at. I have seen something like this elsewhere but just cannot find it.
Formula as follows:

summary sheet Cell C1 Sep 16

summary sheet Cell E4 =sumif('C1'!$P:$P,summary!a4,'C1'$K:$K)

Any suggestions to avoid 'find and replace' in the formula gratefully received

 

[yky]

Try if the following formula works:

=SUMIF(INDIRECT("'" & $C$1 & "'!$P:$P"),A4,INDIRECT("'" & $C$1 & "'!$K:$K"))

 

[Smithsat34]

yky,

Thanks a million, for some reason I can't get INDIRECT to stick in my head,