a common anode contact at which {TAIL ~ the respective anodes} of all of {HEAD ~ said extraction diodes} are connected together 
a common anode contact at which { TAIL ~ the respective anodes } of all of { HEAD ~ said extraction diodes } are connected together
OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH