Best Free Reference

This 10,000 page reference center is dedicated to providing information to the general public on African American history in the United States and on the history of the more than one billion people of African ancestry around the world.

BHL is a collaborative effort of natural history and botanical garden libraries to digitize their collections and make them available as a global biodiversity commons. In 2009, the effort began to expand globally, and now BHL includes more than 53,000 titles and 102,000 volumes that can be browsed or searched, together covering more than 1,060,000 species. APIs and developer tools are available to assist in re using content. Data files can also be exported to help libraries identify content. BHL includes such collections as the Smithsonian Contributions and Studies Series; Darwin Digital Library of Evolution, from the American Museum of Natural History in New York; Harvard University Botany Libraries’ Orchidaceae Type Specimen Project, Extinct Species; and books from the Institute of Botany, Chinese Academy of Sciences. Great for rare scientific texts.

Use Plant Information Online to discover sources in 1023 North American nurseries for 97248 plants, find 329396 citations to 167618 plants in science and garden literature, link to selected websites for images and regional information about 18101 plants, and access information on 2703 North American seed and nursery firms. Plant Information Online is a free service of the University of Minnesota Libraries.

The Cornell Lab of Ornithology is a world leader in the study, appreciation, and conservation of birds. Our hallmarks are scientific excellence and technological innovation to advance the understanding of nature and to engage people of all ages in learning about birds and protecting the planet.

The IUCN Red List of Threatened Species™ is widely recognized as the most comprehensive, objective global approach for evaluating the conservation status of plant and animal species. From its small beginning, the IUCN Red List has grown in size and complexity and now plays an increasingly prominent role in guiding conservation activities of governments, NGOs and scientific institutions. The introduction in 1994 of a scientifically rigorous approach to determine risks of extinction that is applicable to all species, has become a world standard. In order to produce the IUCN Red List of Threatened Species™, the IUCN Species Programme working with the IUCN Survival Commission (SSC) and with members of IUCN draws on and mobilizes a network of scientists and partner organizations working in almost every country in the world, who collectively hold what is likely the most complete scientific knowledge base on the biology and conservation status of species.

Mark Twain Project Online applies innovative technology to more than four decades' worth of archival research by expert editors at the Mark Twain Project. It offers unfettered, intuitive access to reliable texts, accurate and exhaustive notes, and the most recently discovered letters and documents.

Its ultimate purpose is to produce a digital critical edition, fully annotated, of everything Mark Twain wrote. MTPO is produced by the Mark Twain Papers and Project of The Bancroft Library in collaboration with the University of California Press; the site is hosted by UC Berkeley's Library Systems Office. During 2005–8 the California Digital Library collaborated in MTPO's creation and initial development.

This resource from the Internet Archive (IA) strives to list information on every book every published, be it metadata or scans of actual books. Users can check out and read library books, organized by subject heading such as “health & wellness,” “art instruction,” and “business & finance.” Open Library invites the public to donate books to be scanned and contribute metadata. Although many public and academic libraries have expressed support for the Open Library and its Controlled Digital Lending model, IA is facing an ongoing lawsuit filed in June 2020 by several publishers, accusing the Open Library of distributing “digital bootleg versions” of books online.

Looking for high resolution stock photos for your illustration, comp or design needs? Search Morgue File for free reference images. Yes, they're all completely free. whether you're an illustrator, art director, instructor or looking to add a defining visual to a presentation.

Welcome to the UNESCO Institute for Statistics (UIS) - the primary source for cross-nationally comparable statistics on education, science and technology, culture, and communication for more than 200 countries and territories.

Access hundreds of measures of childhood well-being.

Real-time world statistics

Changes in the Value of Money over time

We are a nonprofit publisher and advocacy organization. Our mission is to accelerate progress in science and medicine by leading a transformation in research communication. Every article that we publish is open-access - freely available online for anyone to use. Sharing research encourages progress, from protecting the biodiversity of our planet to finding more effective treatments for diseases such as cancer.

Welcome to the Stanford Encyclopedia of Philosophy (SEP). From its inception, the SEP was designed so that each entry is maintained and kept up to date by an expert or group of experts in the field. All entries and substantive updates are refereed by the members of a distinguished Editorial Board before they are made public. Consequently, our dynamic reference work maintains academic standards while evolving and adapting in response to new research. You can cite fixed editions that are created on a quarterly basis and stored in our Archives (every entry contains a link to its complete archival history, identifying the fixed edition the reader should cite). The Table of Contents lists entries that are published or assigned. The Projected Table of Contents also lists entries which are currently unassigned but nevertheless projected.

The CyberCemetery is an archive of government websites that have ceased operation (usually websites of defunct government agencies and commissions that have issued a final report). This collection features a variety of topics indicative of the broad nature of government information. In particular, this collection features websites that cover topics supporting the university’s curriculum and particular program strengths.

Wolfram|Alpha introduces a fundamentally new way to get knowledge and answers—
not by searching the web, but by doing dynamic computations based on a vast collection of built-in data, algorithms, and methods.

Butterflies and Moths of North America is an ambitious effort to collect, store, and share species information and occurrence data.

The National Center for Complementary and Alternative Medicine (NCCAM) is the Federal Government’s lead agency for scientific research on the diverse medical and health care systems, practices, and products that are not generally considered part of conventional medicine.

TED is a nonprofit devoted to Ideas Worth Spreading. It started out (in 1984) as a conference bringing together people from three worlds: Technology, Entertainment, Design. Since then its scope has become ever broader.

We are of assistance to peoples of all countries who wish to reveal unethical behavior in their governments and institutions. We aim for maximum political impact.

Disclosed documents are classified, censored or otherwise opaque to the public record. We rely on readers to alert their communities and press to the revelations here.

Your ultimate guide to the shelf life of food.

ProCon.org is a 501(c)(3) nonprofit public charity that has no government affiliations of any kind. Our purpose is to provide resources for critical thinking and to educate without bias. We do not express opinions on our research projects ("issue websites").