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 Red Ghost: An Ewok Adventure is a 1986 children's book adaptation of the thirteenth episode of the Star Wars: Ewoks TV series, entitled "Asha."