Book  (2006)  Page(s) 102.  
 
Gerdo HT (flora-tea) ab 1986 MR11 gives no introducer (Kordes) 

Book  (19 Apr 2000)  Page(s) 186.  
 
Gerdo, HT, ab, 1986

Book  (1999)  Page(s) 266.  
 
'GERDO'
MODERN, CLUSTER-FLOWERED/FLORIBUNDA, APRICOT BLEND, REPEAT-FLOWERING
......grown in vast quantities under glass for the cut-flower trade..... soft apricot-fawn color that are produced both singly and several to a stem...... There is no scent. ..... low bush with glossy dark green foliage and is prone to black spot.....Kordes, Germany, 1991. Sport of 'Mercedes'