id	keyword
ajst-23430	gas
ajst-23430	pollution
ajst-23430	international
ajst-23430	environmental
ajst-23430	gas pollution
ajst-23430	system
ajst-23430	cooperation
ajst-23430	energy
ajst-23430	countries
ajst-23430	control
ajst-23430	mechanism
ajst-23430	disputes
ajst-23430	law