In 1934, Verardo García Rey gathered the vocabulary of the Bercian dialect in the publication: Vocabulario de El Bierzo, where the author makes clear that after his fieldwork, he would re-place the dividing line between the Asturleonese and the Galician-Portuguese linguistic groups, setting it strictly along the Sil river.
En 1934, Verardo García Rey, recolle o vocabulario do dialecto berciano na publicación Vocabulario del Bierzo, onde o autor explica que tras o seu traballo de campo, resituaría a franxa divisoria entre as falas asturleonesas e as galaico-portuguesas axustándoa estritamente ao trazado debuxado polo curso do río Sil.