Wendy Wax. (2007). Piggley Makes a Friend (Ready-to-Read. Level 1). Simon Spotlight.
芝加哥风格引文Wendy Wax. Piggley Makes a Friend (Ready-to-Read. Level 1). Simon Spotlight, 2007.
MLA引文Wendy Wax. Piggley Makes a Friend (Ready-to-Read. Level 1). Simon Spotlight, 2007.
警告：这些引文格式不一定是100％准确.