Said invention provides self luminosity by means of a plurality of {HEAD ~ glass microspheres} containing {TAIL ~ both a light emitting phosphor} and a radioactive gas 
Said invention provides self luminosity by means of a plurality of { HEAD ~ glass microspheres } containing { TAIL ~ both a light emitting phosphor } and a radioactive gas
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH