- HörbuchA PulleyDavid Armentrout
- HörbuchHistoric Sites & MonumentsDavid Armentrout
- HörbuchAn Inclined PlaneDavid Armentrout
- HörbuchA LeverDavid Armentrout
- HörbuchA WedgeDavid Armentrout
- HörbuchA WheelDavid Armentrout
- HörbuchA ScrewDavid Armentrout
- HörbuchDirt BikesDavid Armentrout
- HörbuchHistoric & Famous CitiesDavid Armentrout
- HörbuchStunts, Tricks, and JumpsDavid Armentrout