Riordan, R. (2012). The Heroes of Olympus The Mark of Athena. Penguin Books Ltd.
芝加哥风格引文Riordan, Rick. The Heroes of Olympus The Mark of Athena. Penguin Books Ltd, 2012.
MLA引文Riordan, Rick. The Heroes of Olympus The Mark of Athena. Penguin Books Ltd, 2012.
警告：这些引文格式不一定是100％准确.