- E-bookThe Callisto Group and the Crime of the CenturyMichael Westheim
- E-bookThe Callisto Group and the Journey to EarthMichael Westheim
- E-bookThe Callisto Group and the Big, Bad WolfMichael Westheim
- E-bookThe Callisto Group and the Impending CatastropheMichael Westheim
- E-bookSerie: The Callisto SeriesMichael Westheim