North American Immigrant Letters, Diaries and Oral Histories includes thousands of authors and approximately 100,000 pages of information, thus providing a unique and personal view of what it meant to immigrate to America and Canada between 1800 and 1950. Composed of contemporaneous letters and diaries, oral histories, interviews, and other personal narratives, the series provides a rich source for scholars in a wide range of disciplines. In selected cases, users will be able to hear the actual audio voices of the immigrants.

North American Women's Letters and Diaries is the largest collection of women's diaries and correspondence ever assembled. The database covers a period of 300 years. -- Die nordamerikanischen Frauenbriefe und Tagebücher sind die größte Sammlung von Tagebüchern und Briefkorrespondenzen, die je zusammengestellt wurden. Die Datenbank umfasst einen Zeitraum von 300 Jahren.

O'Reilly is an electronic reference library by providing access to technical content from leading publishers, including books, videos, proven learning paths, case studies, interactive tutorials and audio books. The learning platform gives access to the latest titles from O'Reilly and from Pearson's collection of imprints which include: Addison-Wesley Professional, Adobe Press, Cisco Press, Macromedia Press, New Riders, Peachpit Press, Prentice Hall PTR, Sun Microsystems Press, Que, and Sams. Microsoft Press titles are also available in O'Reilly.

OLC Economic Sciences is a subject oriented selection of bibliographic data from the Online Contents database that is regularly enhanced by table of contents data from 3,150 additional periodicals with more than 4,500,000 records of articles out of the special collections of the ZBW – Leibniz-Informationszentrum Wirtschaft and the university library of the Helmut Schmidt university, Federal Armed Forces, Hamburg.

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.

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.

Developed cooperatively with scholars and librarians worldwide, Oxford Bibliographies offers exclusive, authoritative research guides across a variety of subject areas. Combining the best features of an annotated bibliography and a high-level encyclopedia, this cutting-edge resource directs researchers to the best available scholarship across a wide variety of subjects.

Oxford Handbooks Online is a collection of handbooks in 17 subject areas, bringing together the world's leading scholars to write review essays that evaluate the current thinking on a field or topic, and make an original argument about the future direction of the debate. For the first time, all Handbooks are available online as well is in print across the subject areas. Monthly updates introduce articles in advance of print publication and beyond the book, online-only content ensures the most current, authoritative coverage anywhere.

Including Oxford Scholarship Online (OSO), the University Press Scholarship Online (UPSO) publishes new books every month from an ever-growing roster of contributing presses, each adding to the variety of subjects covered on the platform. The MPG purchased the volumes 2003-2013/2014 of 16 OSO subject collections. This selection is continuously extended by single e-book acquisitions by MPG libraries.

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 PrimateLit database provides bibliographic access to the scientific literature on nonhuman primates for the research and educational communities. Coverage of the database includes all publication categories (articles, books, abstracts, technical reports, dissertations, book chapters, etc.) and many subject areas (behavior, colony management, ecology, reproduction, field studies, disease models, veterinary science, psychology, physiology, pharmacology, evolution, taxonomy, developmental and molecular biology, genetics and zoogeography).

Project MUSE is a leading provider of digital humanities and social science content for the scholarly community. Since 1995 the MUSE journal collections cover full-text versions of scholarly journals from many of the world's leading university presses and scholarly societies, with over 120 publishers currently participating.

PsycARTICLES comprises journals published by the American Psychological Association, the APA Educational Publishing Foundation, the Canadian Psychological Association, and Hogrefe Publishing Group, from 1894 onwards.

PsycCRITIQUES contains full-text reviews of books in psychology and the social sciences, as well as professional videos and popular films from a psychological perspective. Reviews occasionally include comparative or retrospective book reviews. The database also includes all reviews published in the print journal Contemporary Psychology: APA Review of Books between 1956 (Volume 1, Issue 1) and 2004. PsycCRITIQUES ended publication in Fall 2017, the archive is made available by the CCHP in partnership with the APA.

The PsycINFO databases cover the professional and academic literature in psychology and related disciplines including medicine, psychiatry, nursing, sociology, education, pharmacology, physiology, linguistics, and other areas. Coverage is worldwide, and includes references and abstracts to over 1300 journals and to dissertations in more than 30 languages, and to book chapters and books in the English language. Over 50,000 references are added annually. Popular literature is excluded.

The PsyJOURNALS collection is a diverse portfolio of highly-regarded, peer-reviewed journals in German and English languages published by Hogrefe and by Hans Huber that cover a wide range of areas within psychology and psychiatry. Max Planck researchers have full text access to 31 journals from 2015 onwards, with a two-year moving wall.