O'Brien, E. (2003). Seamus Heaney: Searches for answers. Pluto Press.
芝加哥风格引文O'Brien, Eugene. Seamus Heaney: Searches for Answers. London ; Sterling, Va.: Pluto Press, 2003.
MLA引文O'Brien, Eugene. Seamus Heaney: Searches for Answers. Pluto Press, 2003.
警告：这些引文格式不一定是100％准确.