This paper summarises the MonetDB&#x2F;XQuery work, I&#x27;m on my phone and couldn&#x27;t find a free PDF but I bet there&#x27;s one somewhere. I read this paper while I was an undergraduate, it&#x27;s very accessible.<p><a href="http:&#x2F;&#x2F;dl.acm.org&#x2F;citation.cfm?id=1142527" rel="nofollow">http:&#x2F;&#x2F;dl.acm.org&#x2F;citation.cfm?id=1142527</a>