The method 4 wherein {HEAD ~ the amount} of {TAIL ~ hydrogen} introduced into said coal bed formation is within the range of 0.2–1.0 standard cubic feet for each cubic foot of methane recovered from said coal bed formation 
of
The method 4 wherein { HEAD ~ the amount } of { TAIL ~ hydrogen } introduced into said coal bed formation is within the range of 0.2–1.0 standard cubic feet for each cubic foot of methane recovered from said coal bed formation
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH