(1980). Circle music: 2, for any two or more players / William Hellermann.
芝加哥风格引文Circle Music: 2, for Any Two or More Players / William Hellermann. 1980.
MLA引文Circle Music: 2, for Any Two or More Players / William Hellermann. 1980.
警告：这些引文格式不一定是100％准确.