Reference
Susumu Takamatsu, Uwe Braun (2000): Phylogeny of Erysiphe, Microsphaera, Uncinula (Erysipheae) and Cystotheca, Podosphaera, Sphaerotheca (Cystotheceae) inferred from rDNA ITS sequences - some taxonomic consequences – Schlechtendalia – 4: 1 - 33.