Book  (Apr 1993)  Page(s) 349.  
 
Mainauperle® Hybrid Tea, dark red, 1969, (KORmai); Seedling x 'Americana'; Kordes, R. Description.

Book  (1972)  Page(s) 142.  
 
Dr. Thomas, Victoria.  The New Ones. 
Mainauperle  HT. (Kordes, 1967) is about as dark as 'Crimson Glory' but the colour has much more life in it and it seems not to blue. The blooms are beautifully formed but they open rather quickly under warm conditions. A splendid grower.

Book  (1971)  Page(s) 24.  
 
Roy and Heather Rumsey,  NSW.  New Roses. 
Mainauperle HT. (Kordes). Rich red, with well formed blooms of about 50 broad petals. ('Super Star' x 'President Dr. H. C. Schroeder'.)

Website/Catalog  (1970)  Page(s) 2.  Includes photo(s).
 
Mainauperle (Perla di Mainau) Mainau; la splendida isoletta dal clima mediterraneo, posta sul lago di Costanza, paradiso di esotici fiori. Perla di Mainau: la suprema bellezza di questa nuova rosa rossa ha indotto l’ottenitore ad indicarla come la perla di quest’isola di sogno. I boccioli affusolati dischiudono fiori elegantissimi, leggermente profumati, di colore rosso scuro vellutato e illuminato d’arancio. Pianta molto vigorosa, guarnita d’un fogliame verde lucente, continuamente in fiore da maggio ai geli.

Book  (1968)  Page(s) 131.  
 
...die im Rosenjahrbuch 1967 auf Seite 169 als ADR-Nr. 6415 beschriebene, anerkannte Sorte inzwischen den Namen 'Mainauperle' erhielt und voraussichtlich erst im Herbst 1970 in den Handel kommt.

Translation:
--the recognized variety described in Rosenjahrbuch 1967 on page 167 as ADR-Nr. 6415 has meanwhile received the name 'Mainauperle' and is not expected to go on sale until autumn 1970.