In my opinion, the very best Basque grammar of all times. It describes the Navarrese-Labortan dialect, a koine formerly in use in the continental Basque Country which is extremely similar to the unified Batua dialect (and indeed one of the pilars of Batua). First published in 1951 and improved in 1976, it is a pity there was no third edition. Brief and complete at the same time, a must for any Bascophile. Nowadays, the book is very difficult to find, so enjoy!