{HEAD ~ The present invention} relates to organic light emitting devices , and more specifically to {TAIL ~ phosphorescent organic materials} used in such devices 
relates specifically to
{ HEAD ~ The present invention } relates to organic light emitting devices , and more specifically to { TAIL ~ phosphorescent organic materials } used in such devices
HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL OTH OTH OTH OTH OTH OTH OTH OTH REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH