Villegas, B. M. No way to avoid coal. IN Environmental News. Manila Bulletin.
芝加哥风格引文Villegas, Bernardo M. "No Way to Avoid Coal. IN Environmental News." Manila Bulletin .
MLA引文Villegas, Bernardo M. "No Way to Avoid Coal. IN Environmental News." Manila Bulletin, .
警告：这些引文格式不一定是100％准确.