Article (magazine)  (Jan 1955)  Page(s) 57.  
 
Alphabetical Check List of Tree Peony Names In  Public Collections And/or Available in Nurseries 1954-1955
Japanese, White, 'Hira-no-yuki' (Snow of Hira) (Jap. bef. 1934), [Gardens] University of Washington Arboretum, [Nurseries] William Gratwick

Website/Catalog  (1945)  Page(s) [3].  
 
Rare Plants Tree Peonies
Ready for Your Garden Now.
White
Mountain of Sun-lit Snow (Hira-no-yuki).