Magazine  (Sep 1977)  Page(s) 23.  
 
"Botanical Descriptions of 40 Saunders Lutea Hybrids" by Dr. David Reath and Silvia Saunders
...These descriptions aim to provide the nurseryman and the average gardener with a means of determining the differences between the hybrids, many of which are very similar indeed...
Wings of the Morning—Single; 10 petals, palest yellow, of heavy substance. Furled back. Flares wide and dark; dramatic. Filaments creamy reddish. Stigmas cream-white, sheath cream-white. Anthers uneven lengths. Foliage of heavy substance.

Article (magazine)  (Jan 1955)  Page(s) 24.  
 
Varieties Raised in America. All by Professor Saunders...
The "Roman Gold Group." Yellow, clear or almost clear , generally single.
'Wings of the Morning,' (1948), formerly Aureole

Magazine  (Mar 1954)  Page(s) 22.  
 
Hybrid Tree Peonies
...By far the most important work with these hybrids has been done by Prof. A. P. Saunders and his originations now number about 80. Their color range is truly remarkable. [...]
The list of hybrid tree peonies following is up to date as far as we could make it.
Originations of A. P. Saunders, Clinton, N.Y.
Hybrids of suggruticosa, lutea and Delavayi.
Wings of the Morning, Single, pale yellow, purple flares. 1948.