This database of 1660 working maps was taken from the Catalan linguistic atlas ALDC ("Atles lingüístic del domini català"), whose data was collected between 1964 and 1978 and published in nine volumes by Joan Veny and Lídia Pons i Griera between 1998 and 2019. For the production of the 1660 working maps 788 original maps of the volumes I-IV of the ALDC were used.
In terms of categories, 931 of the 1660 working maps belong to phonetics (of which 430 belong to vocalism and 363 to consonantism) and 729 to lexicon (vocabulary).
ALDC Webpage: https://aldc.espais.iec.cat