Any idea of I am doing wrong?

I guess not enough (UTSL and RTM)-ing :) safe-bet when dealing with SOAP, which I hate :)

See http://guide.soaplite.com/, Re: SOAP::Lite fault seems faulty, Re: Suppressing nil attribute in empty SOAP tag, SOAP::SOM

Since you're using service, when you call you don't get back a SOAP::SOM object on which you can call ->result, you get back the return value of ->result , for which you can use References quick reference to navigate (or Data::Diver).

Using service is like using stubmaker

$ ls

$ stubmaker "http://hal.archives-ouvertes.fr/ws/ref.php?wsdl"

$ ls
Hal_WebServices_ReferentielsService.pm

$ perl -MHal_WebServices_ReferentielsService=:all -le "  print for @{ 
+getRefInstance()->{string} }[1..3] "
afssa
archivesic
artxiker
[download]

See also Re^11: Soap::Lite and Complex Types with WSDL