Google has launched a new search tool aimed at improving the public's access to academic material.
Google's competition is expected to follow suit with their own versions
Google Scholar allows searches for keywords in theses, technical reports, university websites and books.
The free service spans the academic disciplines from medicine and physics to economics and computer science.
Search results are ranked by order of relevance, including the number of citations by other authors, rather than by the number of hits.
Invisible to searchers
While the great majority of recent papers and periodicals are indexed on the web, many have not been easily accessible to the public using normal search engines.
The project involved broad co-operation from academic, scientific and technical publishers to improve indexing of restricted-access material.
However, many of these publications will still require a subscription to the publishing website to be read but short extracts should be available.
Danny Sullivan, editor of the online newsletter SearchEngineWatch, said: "Normally, such material would never get spidered by search engines such as Google, so the material would be invisible to web searchers.
"The advantage is that suddenly, searchers have a much better ability to locate material that may be of interest."
Google Scholar reflects a growing trend over the last decade by students and academics who begin their research with online search engines.
Mr Sullivan predicted that other search engines would soon follow with their own specialised search tools.
"What Yahoo doesn't currently provide is a specialised way to search through just this material. It's quite likely in my view that this will come," he said.