A method for {HEAD ~ the storage} of hydrogen within {TAIL ~ a subterranean solid carbonaceous formation} such as a coal seam 
A method for { HEAD ~ the storage } of hydrogen within { TAIL ~ a subterranean solid carbonaceous formation } such as a coal seam
OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH