- UBC Botanical Garden
- ARS Botanical Index
- Mount Arrowsmith Rhododendron Society
- Vireyas
- Group for the Rhododendron Lover
- Victoria Horticulture Society
- Societe Brittone du Rhododendron (near Cherbourg, France)
- Meerkerk Rhododendron Gardens
- Georgia Native Azaleas
- University of Victoria Finnerty Gardens
- Victoria Rock and Alpine Garden Society (VIRAGS)
- Mason - Dixon Chapter of the American Rhododendron Society
- Horticultural Glossary
