Website/Catalog  (2012)  Page(s) 331.  Includes photo(s).
 
Danubio Azul, Camprubi, 1957, HT, lilac, bluish when expanding, passing to homogenous cobalt and mauve when development is completed, double, cupped, medium size, mild fragrance, Tristesse X Independence, upright growth, [bibliography] C - MCF10

Book  (1958)  Page(s) 76.  
 
Danubio Azul. HT. (Camprubi Nadal, '57.) Tristesse X Independence. Medium size, dbl., cupped, slightly fragarnt, lilac. Upright; abundant bloom.