Book  (Oct 2001)  Page(s) 113.  Includes photo(s).
 
Clematis 'Andrew'
Magnus Johnson (Sweden) c. 1952
Chance seedling of C. 'Prins Hendrik'
... single, bluish violet flowers... eight overlapping tepals, each with shades of purple at the base of the middle bar and wavy margins. The stamens are made of white filaments and purplish violet anthers...