Originally Posted by StuartReeves
Yes but... Lommar
by Lars Jonsson apparently concentrates on the field identification of the various species of diver, but also covers e.g. distribution and behaviour and no doubt has fantastic illustrations. Unfortunately it is both out of print and written entirely in Swedish.
I've a copy of Lommar and can confirm that it's on ID and that the plates are superb. Apologies for the poor photos attached but my scanner's playing up so I took photos with my mobile. It's a slim 80-page booklet and is indeed in Swedish. Many years ago my wife taught herself Swedish to read Tove Jannsen's Moomin books in the original language and kindly translated the captions under the plates. Alas, she never got round to translating the whole book.