Ebsco Discovery Service: 600 million articles
Google Scholar: 150 mil 25% includes a lot of patents and case law
Scopus: 74 million 12.5 %
Web of Science: 90 mil (4470 journal titles) 15%
Ebsco Discovery Service is the search engine of the UMass Lowell Libraries. It indexes 600 million articles including Elsevier, Wiley, Springer, IEEE, APA and most major academic publishers and professional association.
All of the content indexed by EDS is either available to the UMass community in full text. online or overnight from interlibrary loan.