Altman, D. (2005). Unjustified restrictions on letters to the editor. Public Library of Science.
芝加哥风格引文Altman, D. Unjustified Restrictions on Letters to the Editor. Public Library of Science, 2005.
MLA引文Altman, D. Unjustified Restrictions on Letters to the Editor. Public Library of Science, 2005.
警告：这些引文格式不一定是100％准确.