Scitopia.org - Locate a Scientific Document

If you need to research anything related to science in any sort of professional way, fountains of information like Wikipedia might not cut it. For such queries, you're going to need a more professional, accurate, and genre-specific search tool like Scitopia. Scitopia is a search engine for scientific documents that pulls results from fifteen different scientific organizations spanning the course of 150 years of scientific history. You have several different options when it comes to the search itself, ranging from a simple keyword search to an advanced search which lets you specify the publication title, author, dates, affiliation, and a few other choices. Scitopia automatically sorts your results by relevance, but you can also choose to filter them by date or type (government document, public document, or patent). Remember that often, you'll need to have a membership with the participating organizations to be able to access a document that they provide; Scitopia merely hosts these links, it doesn't grant free access to the content itself. If you don't have access to a document you wish to view because you aren't a member of the organization that is hosting it, you can use Scitopia's pay-per-view option.

"The federated vertical search portal scitopia.org was created through the imagination and collaboration of 15 leading science and technology societies.
Searching for a better way to help researchers quickly get to the quality content they need, these society publishers developed a gateway to the research most cited in scholarly work and patents. Scitopia.org searches the entire electronic libraries of the leading voices in major science and technology disciplines and provides relevant results, without the noise of other Internet search engines. More than three million documents, including peer-reviewed journal content and technical conference papers, spanning 150 years of science and technology can be searched through the site".

Scitopia is a powerful search engine which provides a lot of results for a given search term. You'll have no problem hunting down the information you need, providing that you are able to access to the document in question. Scitopia transcends the boundaries of other simpler genre-specific search engines by providing you with the option of creating an account to store your favorite articles. The pay-per-view option eliminates the need for signing up and paying for access to articles on each of the fifteen sites.

How much is the pay-per view option? What is the difference between results that are displayed automatically and those which Scitopia gives you the option of viewing or not?