BASE - Bielefeld Academic Search Engine. BASE is one of the world's most voluminous search engines especially for academic open access web resources.
BASE is operated by Bielefeld University Library. As the open access movement grows and prospers, more and more repository servers come into being which use the "Open Archives Initiative Protocol for Metadata Harvesting" (OAI-PMH) for providing their contents. BASE collects, normalises, and indexes these data. BASE provides more than 50 million documents from more than 2,900 sources. You can access the full texts of about 75% of the indexed documents. Springer Exemplar. AuthorMapper - Scientific Research and Author Locations Globally.
CiteSeerX. TechXtra: Engineering, Mathematics, and Computing. JURN : search over 4,000 free scholarly ejournals in the arts & humanities. Scirus - for scientific information.