This French magazine on the Pyrenees – with a literary style & design – published in 2006 an edition on the border aspects of the Pyrenees. Charles Darrieu told me about it and helped me to receive it. Bibliographic data:
Les feuilles du Pin à Crochets numéro 7 – Pyrenées frontières
Pau : Éditions du pin à crochets, 2006. – ISBN 2-911715-32-2 (website: http://www.editionspinacrochets.com)

It contains 7 articles on a variety of Pyrenean border issues and is illustrated by lots of b&w pictures, including old pictures of borderpasses.

One of the articles has a link with a previous post on this blog. It’s about a ‘disputed’ triangular area between the summit of le Grand Batchimale (or Pic Schrader) and the borderpass with the original bm330. That borderpass was originally named Port de Clarabide but nowadays is shown on the maps as Port d’Agues-Tortes. The current Port de Clarabide is a few kilometers to the east.
The article shows lot of map-samples from over the years and also on older maps we see usually the name Port d’Agues-Tortes or similar. Only a few give it the name ‘Port de Clarabide’.