And some code for PUA realization :)
Skeleton code here :

use LWP::Parallel;
use HTTP::Request;

my %Engines = )
  google => { url=>'qqq', parse => sub {},},
  av     => { url=>'zzz', parse => sub {},},
)

my $pua = LWP::Parallel::UserAgent->new();
$pua->register($_->{url}, $_->{parse}) for values %Engines;
$pua->wait();
# at this point you have all pages fetched and filtered thru parse sub
+s
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