Book  (Jan 2000)  Page(s) 19.  
 
Page 19: [Bockstoce's] most unusual cultivar is 'Bess Bockstoce', known as 'Rose Heart' in Canada, an unusual, fragrant double whose flower opens as a solid rose and changes to a pink center surrounded by a broad band of white. Upon his death, his stock plants and seedlings went to Henry Landis, a Canadian collector who distributed them on a very limited basis.
Page 163: Bess Bockstoce Herbaceous Peony. Bockstoce 1955. Called 'Rose Heart' in Canada. A double rose hybrid

Magazine  (Sep 1963)  Page(s) 25.  
 
Originations of W. S. Bockstoce [Included with his obituary]
Note: All these are hybrids of Officinalis Rubra and some lactiflora variety.
Bess Bockstoce (1955). D. E. LP. Medium height, good stem, light showy pink.