Book  (Apr 1993)  Page(s) 356.  
 
Margo's Sister Polyantha, shell pink, 1954, 'Margo Koster' sport; Ratcliffe.

Book  (Jun 1992)  Page(s) 247.  
 
Margo's Sister Polyantha. Ratcliffe, 1954. Sport of 'Margo Koster'. Light pink.

Book  (1958)  Page(s) 220.  
 
Margo's Sister. Pol. (Ratcliffe, '54.) Margo Koster sport. Cupped, fragrant, shell-pink. (14)