See article at https://www.luxroots.org/Presse/Voix20081108.pdf
See Annales [put Annales in the search at the top of page for 127 issues of Annales] at this site: https://neptun.unamur.be/s/neptun/neptun_search?filters%5Bmatch%5D=all&filters%5Bqueries%5D%5B0%5D%5Bfield%5D=all_field_search&filters%5Bqueries%5D%5B0%5D%5Boperator%5D=contains_all_words&filters%5Bqueries%5D%5B0%5D%5Bterm%5D=annales&limit%5Bitem_set_title%5D%5B0%5D=Annales%20de%20l%27Institut%20arch%C3%A9ologique%20du%20Luxembourg
Vol. 10 (1878) has an alphabetical list of places in Belgium and also a detailed description of the Beaumont Law.