If formulae with multiple conditions

I guys i have this formulae to sum cell Q34 and Q35 of sheet "INVOICE"

The formulae is

=IF(Q35>0,Q34+Q35,"")

I need to sum cell Q34 & Q35 if it meets certain criteria
i.e:

1) if q35>0
2) if either p38,p39 or q40>0

I am able to integrate the first criteria.
However I am unable to integrate the second criteria


Can anyone please help me?