Illinois Department of Natural Resources
Section Two: Why is Biodiversity Important?
Explore soil, genetic traits, natural resources, and pollution in a series of lessons that focus on biodiversity. Kids complete experiments to learn more about the importance of varied genes and organisms in an ecosystem.
University of St. Andrews (UK)
University of St. Andrews: Biography of Hero
This University of St. Andrews site contains information on the life of Heron as well as his accomplishments.
University of British Columbia
University of British Columbia: Heron's Criterion
This site from the University of British Columbia describes and provides examples of Heron's Formula.