Crabapple
- Descriptions of a range of species and cultivars with notes on their uses and disease resistance. The information from Clemson University is particularly relevant to South Carolina.
- http://hgic.clemson.edu/factsheets/HGIC1007.htm

TreeHelp.com: Crabapple
- A long article covering recommended varieties, cultivation, and common pests and diseases.
- http://www.treehelp.com/trees/crabapple/

Malus - Wikipedia
- An article covering general information on the genus, with photographs, descriptions, cultivation advice and uses for the fruit.
- http://en.wikipedia.org/wiki/Malus