{HEAD ~ VREF} is fed back to {TAIL ~ the bases} of transistors 106 and 108 
is fed back to
{ HEAD ~ VREF } is fed back to { TAIL ~ the bases } of transistors 106 and 108
HEAD HEAD HEAD HEAD HEAD REL REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH