Can sumif work across multiple pages without naming each individual page e.g.
=SUMIF('P0195'!$A:$A,'Sum Parent'!$A19,'P0195'!B:B)+SUMIF('P0196'!$A:$A,'Sum
Parent'!$A19,'P0196'!B:B)+SUMIF('P0197'!$A:$A,'Sum
Parent'!$A19,'P0197'!B:B)+SUMIF('P0198'!$A:$A,'Sum
Parent'!$A19,'P0198'!B:B)+SUMIF('P0199'!$A:$A,'Sum
Parent'!$A19,'P0199'!B:B)+SUMIF('P0200'!$A:$A,'Sum
Parent'!$A19,'P0200'!B:B)+SUMIF('P0201'!$A:$A,'Sum
Parent'!$A19,'P0201'!B:B)+SUMIF('P0202'!$A:$A,'Sum
Parent'!$A19,'P0202'!B:B)+SUMIF('P0203'!$A:$A,'Sum
Parent'!$A19,'P0203'!B:B)+SUMIF('P0204'!$A:$A,'Sum
Parent'!$A19,'P0204'!B:B)+SUMIF('P0205'!$A:$A,'Sum
Parent'!$A19,'P0205'!B:B)+SUMIF('P0206'!$A:$A,'Sum
Parent'!$A19,'P0206'!B:B)+SUMIF('P0207'!$A:$A,'Sum
Parent'!$A19,'P0207'!B:B)+SUMIF('P0208'!$A:$A,'Sum
Parent'!$A19,'P0208'!B:B)+SUMIF('P0209'!$A:$A,'Sum Parent'!$A19,'P0209'!B:B)