BBY/ABY is used to position items along the Star Wars Timeline. BBY refers to Before the Battle of Yavin. ABY refers to After the Battle of Yavin. The Battle of Yavin in Episode IV: A New Hope occured in 0 BBY/ABY.
The White Witch: A Droid Adventure is a 1986 children's book adaptation of the Star Wars Droids episode entitled "The White Witch". It was written by Emily James and illustrated by Bunny Carter.