Introduction to Semistructured Data:
*) XML
*) XML schema languages (DTDs, XML Schema)
*) XML query languages (XPath, XQuery, XSLT)
*) XML-APIs (parsers, XSLT-processor)
"XML in a Nutshell"
von Eliotte Rusty Harold, W. Scott Means
O'Reilly, 3. Auflage, 2004