Book  (Oct 2001)  Page(s) 168.  Includes photo(s).

Book  (1999)  Page(s) 235.  Includes photo(s).
 
...double white flowers with yellow anthers...

Book  (1999)  Page(s) 130.  
 
Clematis 'Duchess of Edinburgh', cv., 1967

Book  (11 Nov 1996)  Page(s) 37.  

Website/Catalog  (1926)  Page(s) 55.  
 
Duchess of Edinburgh, blanc double.

Website/Catalog  (1924)  Page(s) 106.  
 
Duchesse d'Edimbourg (Florida). Blanche double, sépales imbriqués, forme parfaite.

Website/Catalog  (1920)  Page(s) 27.  
 
Clematis...Duchess of Edinburgh, white double...1 piece M 6.-

Book  (1915)  Page(s) 176.  
 
Clematis. — There is no more popular hardy climber than the Clematis.  One or two should be grown in the smallest garden.  They can be used to cover any structure from a few feet to 50 feet high.  A selection of different sorts will ensure a succession of flowers from April to October. [...] There are numerous named varieties; a dozen of the best to furnish flowers from May to October are as follows:
Duchess of Edinburgh, pure white...

Website/Catalog  (1914)  Page(s) 109.  
 
Large Flowering Clematis
Duchess of Edinburgh. One of the best double whites, of vigorous habit, very free of bloom and delightfully fragrant.

Website/Catalog  (1912)  Page(s) 77.  
 
Spring & Summer Flowering Clematis.
Flowering during May, June and July.
As these flower upon the ripened wood of preceding year's growth, they must be but slightly pruned in winter.
Duchess of Edinburgh, the best of the double white varieties, deliciously scented...  2s. 0d