id	keyword
ajst-29852	methane
ajst-29852	coalbed
ajst-29852	development
ajst-29852	gas
ajst-29852	technology
ajst-29852	china
ajst-29852	seam
ajst-29852	mining
ajst-29852	production
ajst-29852	resources
ajst-29852	exploration
ajst-29852	utilization
ajst-29852	energy
ajst-29852	methane development
ajst-29852	coal seam
ajst-29852	permeability
ajst-29852	area
ajst-29852	cbm