Question: What Tibetan language has the initials 'adx'?
Answer(s):
answer: Amdo Tibetan

SPARQL query:
PREFIX ns: <http://rdf.freebase.com/ns/>
SELECT DISTINCT ?x
WHERE {
FILTER (?x != ns:m.01kbrp)
FILTER (!isLiteral(?x) OR lang(?x) = '' OR langMatches(lang(?x), 'en'))
ns:m.01kbrp ns:language.language_writing_system.languages ?x .
?x ns:language.human_language.iso_639_3_code "adx" . 
}