The database OLC Physics is a subject oriented selection of bibliographic data from the Online Contents database that is regularly enhanced by table of contents data from additional periodicals out of the special collections of the TIB Hannover, the central subject library of Germany for technology and their related subjects, especially chemistry, computer sciences, mathematics and physics.

The Online Contents service of the Special Subject Collection Political Science and Peace Research is part of the Online Contents database. It offers access to tables of contents of more than 870 journals relevant for study and research. New journals were added until December 2013 by the Special Subject Collection. Thus the database contains approximately 1.478,600 records of journal articles and reviews.

OLC Psychology is a subject oriented selection of bibliographic data from the Online Contents database. This database is regularly enhanced by table of contents data from additional periodicals out of the special collections of the Saarland University and State Library (SULB) Saarbrücken, the central subject library for Psychology in Germany. Currently 878 journals are being indexed back to the year of publication in 1993.

Online Contents Social Sciences provides access to the tables of contents of journals in the field of sociology and social policy. It is a subject-oriented selection of bibliographic data from the Database Online Contents. The database is regularly enhanced by table of contents data from additional periodicals out of the special collections of the University Library Cologne.

OLC Technology is a subject oriented selection of bibliographic data from the Online Contents database that is regularly enhanced by table of contents data from additional periodicals out of the special collections of the TIB Hannover, the central subject library of Germany for technology and their related subjects, especially chemistry, computer science, mathematics and physics. Currently 2,393 journals are being indexed back to the year of publication in 1993.

The Open Library of Humanities is an open access publishing platform, launched as an international network of scholars, librarians, programmers and publishers in January 2013. The OLH platform supports academic journals from across the humanities disciplines, as well as hosting its own multidisciplinary journal. Unlike many open-access publishers, the Open Library of Humanities does not charge individual author fees, but covers all costs by cooperating with an international library consortium.

Open Syllabus is a non-profit research organization that collects and analyzes millions of syllabi to support novel teaching and learning applications. Open Syllabus helps instructors develop classes, libraries manage collections, and presses develop books. It supports students and lifelong learners in their exploration of topics and fields. It creates incentives for faculty to improve teaching materials and to use open licenses. It supports work on aligning higher education with job market needs and on making student mobility easier. It also challenges faculty and universities to work together to steward this important data resource. Open Syllabus currently has a corpus of nine million English-language syllabi from 140 countries. It uses machine learning and other techniques to extract citations, dates, fields, and other metadata from these documents. The resulting data is made freely available via the Syllabus Explorer and for academic research. The project was founded at The American Assembly, a public policy institute associated with Columbia University. It has been independent since 2019. All of the syllabi in the current collection are English language documents – including from universities where English is not the primary teaching language.

Founded in 1916, Optica (formerly the Optical Society of America, OSA) was organized to increase and diffuse the knowledge of optics, pure and applied. One of the Society's major activities is the publication of peer-reviewed journals, books, conference proceedings and co-publications.

Founded in 1916, Optica (formerly the Optical Society of America, OSA) was organized to increase and diffuse the knowledge of optics, pure and applied. One of the Society's major activities is the publication of peer-reviewed journals and books. Though access to current Optica Publishing Group content is no longer licensed, access to the 2007 - 2011 volumes of the journals and proceedings is still available.

The OSF Preprints search combines records from various preprint repositories, including arXiv, bioRxiv, Cogprints, PeerJ, PsyArXiv, RePEc and SocArXiv.

Oxford Bibliographies offers exclusive, authoritative research guides. Combining the features of an annotated bibliography and a high-level encyclopedia. Every article in the database is an authoritative guide to the current scholarship, written and reviewed by academic experts, with original commentary and annotations.

Oxford Bibliographies in International Law offers exclusive, authoritative research guides that combine the best features of an annotated bibliography and a high-level encyclopedia. The database provides a comprehensive introduction to the essential body of literature that has shaped scholarly thought. It provides expert recommendations on the works available in International Law whether it be a chapter, a book, a journal article, a Website, blog, or data set. The entries provide a critical reflection on the literature and define the concepts necessary for legal aspects of international problems. The module “International Law” comprises e.g. the following main subjects: “History of International Law”, “Human Rights”, “International Economic Law”, “International Environmental Law”, “International Humanitarian Law”, “Sources, Foundations, and Principles of International Law”, “Specific Nations and Regions”, “Territory and Sea Law”, “Theory of International Law”. RSS alerts notify you when articles and bibliographies are updated.

The platform serves as interface to over 300 journals published by the Oxford University Press (OUP) in the humanities, social sciences, law, science, and medicine. Two-thirds of this journals are published in partnership with learned and professional societies around the world. The MPG subscription enables full text access to OUP's full journal collection. It also covers article-processing charges for Max Planck authors in hybrid and selected fully open access journals offering CC-BY licenses. Further details are available on the MPDL website.

The Oxford Legal Research Library provides access to leading works relevant to "International Commercial Arbitration" as well as "International Commercial Law" and "Private International Law". A title list can be found at https://olrl.ouplaw.com/page/476/ (the product "Financial and Banking Law" is not licensed).

Oxford Music Online contains the full text of several music reference works, most importantly Grove Music Online, The Oxford Companion to Music, and The Oxford Dictionary of Music

PeerJ is an Open Access, peer-reviewed, scholarly journal. It considers and publishes Research Articles in the Biological and Medical Sciences. It aims for rapid decision making and will publish articles as soon as they are ready. PeerJ operates a 'Lifetime publishing plan' model. Unlike many Open Access publications which charge authors per publication, PeerJ provides low-cost publishing plans to individuals, which gives them lifetime rights to publish with PeerJ for free. The Max Planck Society covers the Enhanced Publication Plan for all Max Planck authors centrally. Further details are available on the MPDL website.

Periodicals Archive Online is a major archive that makes the backfiles of scholarly periodicals in the arts, humanities and social sciences available electronically, providing access to the searchable full text of hundreds of titles. The database spans more than two centuries of content, 37 key subject areas, and multiple languages.

This historic journal index enables the simultaneous search in millions of citations for articles published in the arts, humanities and social sciences, across more than 300 years. It enables researchers quickly and comprehensively to identify articles relevant to their field of study and reduces what could take years of research to a matter of minutes. Journals indexed span 37 key subject areas and multiple languages.

The "JPS Journals" platform provides access to the academic journals published by the Physical Society of Japan (JPS). These journals cover the subject area from condensed matter physics to particle physics.

PLOS (Public Library of Science) is a nonprofit publisher and advocacy organization founded to accelerate progress in science and medicine by leading a transformation in research communication. PLOS entered the publishing arena in October 2003 with the launch of PLOS Biology, followed in October 2004 by PLOS Medicine. Today, it publishes a suite of influential Open Access journals across all areas of science and medicine. The Max Planck Society covers article-processing charges for Max Planck authors centrally. Further details are available on the MPDL website.