"Perl XML::LibXML by Example" by Grant McLean is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License (see also human-readable summary).
The preferred form of attribution is via a link to http://grantm.github.io/perl-libxml-by-example/.
The source code for this work is at: https://github.com/grantm/perl-libxml-by-example.