International Society For The Vascular Anomalies
- The official site of the International Society for the Study of Vascular Anomalies.
- http://www.issva.org

Birthmarks.com
- This site offers information and helpful sites related to various port-wine stain and other birthmarks, including contact information for physicians in this field.
- http://www.birthmarks.com

AR Children's Hospital Birthmarks Homepage
- This site has detailed information on birthmarks, particularly on hemangiomas.
- http://www.birthmarks.org

Mongolian Spots - DrGreene.com
- Read an article that describes spots on the skin that are sometimes mistaken for bruises.
- http://www.drgreene.com/21_1143.html

Vascular Birthmarks Foundation
- An international charitable organization that provides support and informational resources for individuals affected by hemangiomas, port wine stains and other vascular birthmarks and tumors. Also sponsors relevant research.
- http://www.birthmark.org/