Magazine  (2017)  Page(s) 20.  
 
I found 6 German rose nurseries represented with novelties: Conrad Maaß with the roses Marie Maaß, Conrad Maaß and Franz Grümmer.

Book  (1936)  Page(s) 439.  
 
Maass, Maria (HT) Maass 1927; K. Aug. Viktoria X Mar. Niel; pure white to ivory-white-yellow shaded with light pink, very large, very double, fine form, opens, lasting, solitary, fragrance 7/10, floriferous with interruptions, long strong upright stems, lasting foliage, growth 6710, upright, bushy, Sangerhausen