1. L. L. Andersen, and R. M. Callahan (1987 ): An overview of European children's zoos . In Proceedings, from the first international children's zoo symposium, The Philadelphia Children's Zoo, 1-4 July 1987: 133 -139 . Philadelphia: The Philadelphia Children's Zoo.
2. L. L. Andersen(1987 ): The new children's zoo at the Copenhagen Zoo . Journal of the International Association of Zoo EducatorsNo. 17: 59 -62 .
3. L. L. Andersen(1988 ): Zoo formidling, Masters thesis , University of Copenhagen, Zoological Museum. [In Danish.].