Curated OER
Kids Health: Acne
The bane of a teenager's existence--acne--is the topic of this informative article. You'll probably learn more than you really wanted to know about it, but the facts are presented in an interesting way. There's even a video to watch.
Other
Acne treatment.net: Six Types of Acne
Do you think pimples are all the same? Read about the six types of acne, and learn about some ways to cope with and treat these skin conditions.
Stanford University
Stanford Encyclopedia of Phil.: Principia Mathematica
This site from the Stanford Encyclopedia of Philosophy briefly explains the history and significance of the famous logical treatise by Whitehead and Russell. Lists the table of contents from each of its three volumes.