Getting XML nodes that have not a fixed place in the XML

I have XML files that i get via a URL http (eg. From these files i want <extref> nodes (more precise the doc attribute within these elements). I thought that xpath with //extref would do the job but i just get one row.

How can i solve this?

So after trying many things with the Xpath node i found it myself. First the XML-reader to download the file. Then the Xpath node with "/*//extref". That's all that's to it.