Dalhem - Herve. Carte géologique de Wallonie à l'échelle 1:25.000. 42/3-4. Notice explicative ; Dalhem - Herve. Geological map of Wallonia at the scale of 1:25.000. 42/3-4. Leaflet

New geological map of Wallonia published at the scale of 1/25.000, based on a new field work and using scientific data produced since the previous edition of Forir published in 1896 at the scale of 1/40.000 by the "Commission Géologique de Belgique". ; Programme de révision de la carte géologique de la Wallonie. Recherches collectives d'intérêt général.