Hi everyone,
This isn't a book but it's still worth having and incredibly useful which is "Conservation International - Frogs of Madagascar, Genus Mantella: Pocket Identification Guide".
This small pocket sized guide/leaflet contains information about all 16 members of the Mantella genus along with some Confer species and Locality variations too. The leaflet is laminated and completely in bright color so you're able to identify individuals, you will also find a section on the back page which enables you too jot down any localities you may come across (proving to be a useful aid whilst searching for Mantella in Madagascar.
You will find information about all the individual 16 species on the back pages (pictured above) allowing you to be able to identify competently any Mantella.
For a mere £6.99, I would say it's well worth the money and a useful tool/aid for any Mantella enthusiast!
Thank you all for reading and enjoy.
Josh