This was a bit harder..
I named the souces V0,1 V0,2 and V0,3.. The impedances are Z1 to Z6, with I1 to I6 flowing through and potential V1 to V6 across. Do not get confused with V0,1 and V1..
I get into the problem that i try to replace e.g. I3 by other currents, but then I get back to the start with Z3I3..
Another problem.. Shouldn't V0,1+V1 = V0,1+V2? Since the potential at the top is the same, and the potential at I0 is the same..? But then V1=V2, which is not true..?