Other
University of Leicester: Irregular Galaxies
Provides a general overview of irregular galaxies, including a specific look at type I and type II irregulars.
US Department of Energy
Fermilab: Questions About Physics: Big Bang & Bosons
What are serious scientists are saying about bosons? This site provides text correspondence between two scientists in question-answer format. Shows why bosons are so important in particle physics.
Science Struck
Science Struck: Nitrogen in the Atmosphere
Learn about the properties of nitrogen, how it was first formed, where it is found, and the importance of the nitrogen cycle.