Karen Ball. (2019). "Leonardo Da Vinci (Young Reading Level 3) [Paperback] [Jan 01, 2010] NILL". Usborne.
芝加哥风格引文Karen Ball. "Leonardo Da Vinci (Young Reading Level 3) [Paperback] [Jan 01, 2010] NILL". Usborne, 2019.
MLA引文Karen Ball. "Leonardo Da Vinci (Young Reading Level 3) [Paperback] [Jan 01, 2010] NILL". Usborne, 2019.
警告：这些引文格式不一定是100％准确.