There are a number of "Daisy" books in Open Library. What is "Daisy?"

The DAISY digital format helps people who have challenges using regular printed media. There are two types of DAISY eBooks on Open Library: open and protected. Open DAISY can be read by anyone in the world on many different devices. Protected DAISY (with the lock icon) can only be opened using a key issued by the Library of Congress NLS Program.