Book  (1942)  Page(s) 552.  
 
DICK KOSTER. Polyantha. (D. A. Koster '35.)

Book  (1940)  Page(s) 53.  
 
Dick Koster. Pol. (D.A.Koster,'35.) Large, bright salmon-rose to orange; cluster. Vig.

Magazine  (1939)  Page(s) 171.  
 
One who has followed up on the business with polyanthas in containers on the Berlin market, will have ascertained that the varieties have changed dramatically. Currently the main sorts on the Berlin Market are: Verdun, Gabrielle Privat, Dick Koster and Gruss an Aachen, and from 100000 polyantha roses, 30000 are Verdun, 30000 Gabrielle Privat, 20000 Dick Koster....

Book  (1936)  Page(s) 118.  
 
This statue was surrounded in the form of a band by the new light orange and salmon-voloured Polyantha-Rose 'Dick Koster'.