Using XHTML/CSS for an Effective Search Engine Optimization Campaign
http://www.alistapart.com/stories/seo/

Olejniczak, Brandon
List Apart, A
2003

Abstract:

We’re going to be focusing entirely on the benefits of using XHTML and CSS to show you how to improve the readability of your code for search engine spiders, maintain a good content-to-code ratio without going beyond file-size and word-count limits, and how to use CSS to mimic common image effects.