Gabriel Gargallo & Andreas Helbig 
Sylvia Warblers [PDF ebook] 
Identification, Taxonomy and Phylogeny of the Genus Sylvia

Based on phylogenetic research, this complete study of the genus Sylvia describes two new species and establishes identification criteria for all members of the family.
A lengthy introduction explains the background to the research and outlines the main features of the genus. The 25 species are then treated in detail, including the African parisomas, which are here included in the Sylva group.
The species accounts include sections on every aspect of identification, with colour illustrations showing age, sex and racial differences, distribution maps, sonograms, moult and wing diagrams and tables.