Book  (2007)  
 
Kilwinning Hybrid spinosissima, w, Percy H. Wright.
R. spinosissima altaica x Hansen's Yellow.

Article (misc)  (18 Jan 1971)  
 
Personal correspondance Percy Wright to Walter Schowalter:
I have no positive record of my Kilwinning rose, but believe it to be a sib of Hazeldean, Yellow altai, and Loch Lomond, namely R. altaica x pollen of Persian Yellow. It is a cross I'd very much like to repeat.

Website/Catalog  (Feb 1967)  
 
Kilwinning Rose - New. This came as a seedling of Altaica from Percy Wright. Evidently crossed with Harrison's [sic] Yellow or Persian Yellow. The blooms are double, a lovely soft primrose yellow, and borne profusely for two weeks or more. The bush grows up to five feet and is fully hardy here, far superior to the old Harrison's [sic] Yellow. Each $3.00. One only to a customer."