Website/Catalog  (2017)  Page(s) 23.  Includes photo(s).
 
Red Letter Day  Rediscovered old rose. Known parent to many modern red roses. Large spreading bush. Very fragrant.

Book  (2007)  
 
'Red-Letter Day' Hybrid Tea, deep pink, 1914 A. Dickson. Includes description.

Book  (Apr 1999)  Page(s) 445.  
 
Red-Letter Day Hybrid Tea. A. Dickson, 1914. The author cites information from different sources... Scarlet crimson...

Website/Catalog  (1999)  Page(s) 14.  
 
Thought to be extinct, popular in the late 1920’s, our plant was found in a customer’s garden. Pinkish-red with lighter reverse, informal blooms and very fragrant. Tall, semi-double. Very fragrant.

Book  (1997)  Page(s) 216.  
 
....I came upon ‘Mrs. Philip Russell‘ bred in 1927 from ‘Hadley’ and ‘Red Letter Day’ and described as “semi-double dark red, shaded black, pillar or large bush”. 

Book  (Apr 1993)  Page(s) 492.  
 
Red-Letter Day Hybrid Tea, velvety rose-red, white streak in center of inner petals, stamens cinnamon, 1914, Dickson, A. Description.

Website/Catalog  (1989)  Page(s) 6.  
 
'Red Letter Day'. Deep red, semi-single.

Book  (1969)  Page(s) 40.  
 
Rona Hurst. Roses and Genetics. …. a popular garden rose of the ‘twenties ‘Red Letter Day’, with a very high proportion of R. chinensis blood which made it extremely free and perpetual flowering.

Article (misc)  (1954)  Page(s) 41.  
 
Red Letter Day 28 chromosomes

Book  (1952)  Page(s) 251.  
 
Red-Letter Day. HT. (A. Dickson, '14.) Medium size (3½ in.) semi-dbl., velvety rose-red, white streak down centre of inner petals, stamens cinnamon; short stem. Fol. glaucous sage-green. Vig. NRS GoldMedal, '13.