JSTOR is one of the largest and most reputable journal archives in the world. The content set currently available to the Wikipedia editors includes all of JSTOR's archival journal collections and the 19th Century British Pamphlets collection.

Ancestry.com comprises a collection of genealogical, historical, and genetic records. This partnership gives access to the World Explorer membership, which includes all US and international records.

BMJ (originally the British Medical Journal) is a peer-reviewed medical journal.

ProQuest is a multidisciplinary research provider. This access includes ProQuest Central, which includes a large collection of journals and newspapers, Literature Online, the HNP Chinese Newspaper Collections, and the Historical New York Times.

NewspaperARCHIVE.com is an online database of digitized newspapers, with over 2 billion news articles; coverage extends from 1607 to the present from US, Canada, the UK, and 20 other countries.

Adam Matthew Digital publishes databases of primary sources and accompanying supporting material; we have access to a large number of databases relevant to major topics in American and World History.

Newspapers.com includes more than 73 million pages from 3,000+ newspapers. The collection includes some major newspapers for limited periods (e.g., 50 years of the New York Times), but mostly consists of US regional papers from the 1700s to the late 1980s. Free accounts through the Wikipedia Library include access to Newspapers.com Publisher Extra content.