Recently,when defending against e4, i have switched from my beloved Alekhine defence to the more common ...e5. My idea is to play the Open variation of the Ruy Lopez (1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.0-0 Nxe4). I quite like the positions I've got so far, but i think it's time to study the line more seriously.
I wonder if someone can suggest me a good source, not necessarily including very deep lines but just explaining the basic concepts. An alternative might be to study some master games (for example GM Vocaturo, the recent winner of Tata Steel C, uses the open quite often).
What's your suggestion?
Thanks in advance.