Using concatenate as the range in an SUMIF formula

[antony moseley]

HI,

I have the below formula
=SUMIF(D3,$F$2,E3)

Where D3 is =CONCATENATE("'",C3,"'!D:D") and shows '18.10.17'!D:D
Where E3 is =CONCATENATE("'",C3,"'!F:F") and shows '18.10.17'!F:F

but my result come back blank

If I type in the formula I get an result.

I am using this as the sheet '18.10.17' is the changing part of the formula as I go through the dates

Anyone suggest where I am going wrong

Thanks

Antony