Nicoline Winkler 
Dictionnaire onomasiologique de l’ancien gascon (DAG). Fascicule 22 [PDF ebook] 

The DAG is the first onomasiological dictionary of Old Gascon. It covers the period from the earliest extant documents to the 17th century, taking into account all relevant idioms and sources (incl. medieval Latin and regional French). From fascicle 12 onwards the dictionary is published with a new, clearer article structure that provides more scope for semantic description and the presentation of idioms and contexts.