The circuit contains {HEAD ~ a quadritail circuit} formed of {TAIL ~ first, second, third and fourth transistors} whose emitters or sources are coupled together 
formed of
The circuit contains { HEAD ~ a quadritail circuit } formed of { TAIL ~ first , second , third and fourth transistors } whose emitters or sources are coupled together
OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH