Paghat's Garden: Rose Canterbury Bell
- Entry point into more than a dozen pages, each describing a different campanula species or cultivar, with characteristics and photos for each.
- http://www.paghat.com/campanula.html

Jane Grushow: Campanulas
- Pennsylvania rock garden enthusiast presents photos and brief information for four small perennial species.
- http://server1.fandm.edu/people/j_grushow/Genus.html