Perhaps you should try some spelling variations:
regimen administrativo » procedimento administrativo (Expand Search), recurso administrativo (Expand Search), atelier administrativo (Expand Search)
actividades sometidas » actividades domesticas (Expand Search), actividades permitidas (Expand Search), actividades referidas (Expand Search)
"Actividades sometidas al régimen administrativo" » "Actividades sometidas a régimen administrativo" (Expand Search), "Actividades sometidos al régimen administrativo" (Expand Search), "Actividades sometidos a régimen administrativo" (Expand Search)
al regimen » el regimen (Expand Search), del regimen (Expand Search), de regimen (Expand Search)

Try widening your search to All Fields.

You may be able to get more results by adjusting your search query.

• Removing quotes may allow a broader search: Actividades sometidas al régimen administrativo.