Astley, N. &. B. (2003). Happy Birthday Peppa! Ladybird Books.
芝加哥风格引文Astley, Neville & Baker. Happy Birthday Peppa! london: Ladybird Books, 2003.
MLA引文Astley, Neville & Baker. Happy Birthday Peppa! Ladybird Books, 2003.
警告：这些引文格式不一定是100％准确.
APA引文