These books are published in Korea where they become the basis for packages of learning materials, and thousands of students receive copies through their English school. Now some of them are being released in North America and are available through Amazon.
Some of these books are published under the name Crystal Stranaghan, while others are written under the pen names Jean Brown, Rose McDonald and Fred Crystal.
I also write other chapter books that are not specifically for ESL Learners. This includes things like the 13th Floor chapter books. These are mostly published in kindle and print format. Sometimes they are also available for the iPad.