Willoughby, W. W. (1925). Opium as an international problem, the Geneva conferences. John Hopkins Press.
芝加哥风格引文Willoughby, Westel Woodbury. Opium as an International Problem, the Geneva Conferences. Baltimore: John Hopkins Press, 1925.
MLA引文Willoughby, Westel Woodbury. Opium as an International Problem, the Geneva Conferences. John Hopkins Press, 1925.
警告：这些引文格式不一定是100％准确.