- Doctor Josef MengeleHolly Cefrey
- Domestic violenceHolly Cefrey
- What If an Asteroid Hit Earth?Holly Cefrey
- One Life to Lose for My CountryHolly Cefrey
- Oceans (Cefrey, Holly. Biomes.)Holly Cefrey
- Gun violenceHolly Cefrey
- Virtual RealityHolly Cefrey
- Steven CallahanHolly Cefrey
- Frequently asked questions about online gaming addictionHolly Cefrey
- Syphilis and Other Sexually Transmitted Diseases (Epidemics)Holly Cefrey
- Let's Take a HikeHolly Cefrey
- Grasslands (Cefrey, Holly. Biomes.)Holly Cefrey
- The Inventions of Eli WhitneyHolly Cefrey
- Sedimentary Rocks (Cefrey, Holly. Earth Rocks!,)Holly Cefrey
- Race car driversHolly Cefrey
- AIDS (Epidemics!,)Holly Cefrey
- Taylor SwiftHolly Cefrey
- Hallucinogens and Your NeuronsHolly Cefrey
- The PlagueHolly Cefrey
- High speed trainsHolly Cefrey
