Reddit mentions of Birds of Europe: Second Edition (Princeton Field Guides)

I like the Princeton Guide (L. Svensson + others). I'll admit, it's the only guide I've used in Europe, but it's worked well for me.

https://www.amazon.com/dp/0691143927/ref=cm_sw_r_cp_awdb_t1_aYe7AbW5XFWCK

I used This One when I went to Italy last year. It uses illustrations and not pictures, but it’s an excellent book. If you scroll to the bottom of the listing some people posted pictures of the inside of the book.

Here is another that looks great but I don’t own it personally

There's Birds of Europe from Princeton, which is pretty good.

This one is regarded as the best book for general bird identification in europe http://www.amazon.com/Birds-Europe-Second-Edition-Princeton/dp/0691143927

and this one is more specific and takes on the Sylvia-warbler familiy like Subalpine Warbler, Sardinian Warbler Ruepells Warbler and such http://www.amazon.co.uk/Sylvia-Warblers-Identification-Taxonomy-Phylogeny/dp/0713639849

Also regarding #2 picture, a Blackcap would show a much more distinct brown-coloured cap and would be more bulky. This show an Blackcap 1cy http://www.netfugl.dk/pictures.php?id=showpicture&picture_id=56273&language=uk, http://www.netfugl.dk/pictures.php?id=showpicture&picture_id=23434, http://www.netfugl.dk/pictures.php?id=showpicture&picture_id=35937