In reply to brunoschull:
Hi Bruno,
I have both these guides. The former is the comprehensive guide to the French side of the range - so it has nothing on the Argentera and Nasta group (where there is some very fine climbing). The latter is as you say the sport climbing guide to the arriere pays from the coast up to the border.
I also have an Italian language guide to the Argentera and Nasta group. It's called All'ombra della Nasta, and was published by the CAI Cuneo section. I haven't found it on their website (caicuneo.it), but this site may have a copy. https://www.anobii.com/books/All%27ombra_della_Nasta/0157dae30a6dba0993
If you are going to go down there for a look, I would recommend the Coullomb guide as it covers both sides of the range, is pretty comprehensive for walking and scrambling, with a selection of the better climbs, mainly at easier grades. If you decide to dig deeper I would then go for the French and Italian guides.
While I am UK based, I used to spend quite a lot of time down there. These days I spend more time in Chamonix, although I still get down there from time to time.
Steve