Google Scholar has released an option for searching Related Articles, similar to PubMed Related Articles and other databases. Google Scholar is not using a thesaurus as PubMed do, but in advanced search you can limit to 7 broad subjects. With these Related Articles option you can try to search an article of your topic. Maybe you know the title or the author. When you find the article click on the link beneath it. Check this article reference by Judit Bar-Ilan about search engines evaluation:

Clicking the Related Articles link returns 99 related articles and one is for example Greg Notess’ old (yes, 2000 is old in the search engine evaluation world!) article about Search engines inconsistencies from the magazine Online.

I also tried some other smaller subjects within information science and it returns remarkably relevant hits. Nice satisfying option, but my brief evaluations doesn’t say anything about coverage of course. When trying to subject search Google Scholar (which as I said is not easy to do comprehensive) try to use the related articles, beside of free-text searching.