The Title Page has a text box for contributions. The Bloom callout box appears next to the text box tells you purpose of the text box and the language you need to use. The language is the one that is set as Language 2 in the collection.
Type the names of people and how they contributed to the book. Include anyone who wrote, illustrated, edited and so on. Here is one possible format:
Written by: <name>
Illustrations by: <name>
Edited by: <name>
Click Paste Image Credits to paste image credit information into the text box.
This information was set up in the Copyright and License dialog box.
If you need to update it, select and delete the information that was previously pasted and then click Paste Image Credits again.
If you select the CC0 Public Domain license, the Copyright Year and Copyright Holder are hidden.
Format the text in this text box (optional).