낙농 부산물 재생천연가스 생산시설을 준공한 미국
Calgren Completes California Dairy Renewable Natural Gas Facility
한글번역 : http://www.kosen21.org/info/globalNews/globalNewsDetail.do?articleSeq=5411
기사원문 : https://www.renewableenergymagazine.com/biogas/calgren-completes-california-dairy-renewable-natural-gas-20190827