Need to seach phonebook

I want to do a search like "rphonebook:smith 78240" with the API, but it always returns 0 results. I know it can be done because it works on www.googlefight.com

I think it has something to do with turning off quotes: you can't do a phonebook search in quotes. Here's my (non-working) Perl script:

use SOAP::Lite;
my $key='I'm_not_telling';
my $query="rphonebook:smith 78240";
my $googleSearch = SOAP::Lite -> service("file:GoogleSearch.wsdl");
my $result = $googleSearch -> doGoogleSearch($key, $query, 0, 10, "false", "", "false", "", "latin1", "latin1");
print "About $result->{'estimatedTotalResultsCount'} results.\n";