[Wikidata] Filtering Human on the Given Name

Hi to all!

I'm very new to Wikidata sparql, and I've only finished the tutorial.

My question is about filtering people on their given name.

I've tried:

SELECT DISTINCT ?person ?personLabel WHERE {   ?person wdt:P31 wd:Q5.   ?person wdt:P735 ?givenName.   SERVICE wikibase:label { bd:serviceParam wikibase:language "en". }   FILTER(STRSTARTS(?givenName, "A")) } LIMIT 1000

http://tinyurl.com/ydeuxopp

But there are no results (I'm filtering on the person with a given name starting with an "A"). What am I doing wrong? Thanks a lot in advance! Cheers