Pertti Pietarinen started to write Children's books in 2013. So far 13 Chidren's books has been published in English and they all are available as print and as e-book.

Lucy The Cat series contains 11 books. In these books Lucy The Cat, cute and curious Sacred Birman Cat Lucy The Cat tells her engaging and funny stories about her own life. Especially cat lovers enjoy the charming photos. 

Books are:

1. Lucy The Cat
2. Lucy The Cat: LIttle Brother
3. Lucy The Cat Play With Me
4. Lucy The Cat and Little Kittens
5. Lucy The Cat Christmas
6. Lucy The Cat Sushi Time
7. Lucy The Cat Beauty And The Feast
8. Lucy The Cat in Tokyo
9. Lucy The Cat In Tokyo 2
10. Lucy The Cat Enchanted Forest
11. Lucy The Cat Mystery Queen

In addition to Lucy The Cat series inspirational Children's book God's Children was published in 2014 and Kingdom of God in 2014.