Library
University textbooks, each with its licence read on its publisher's own page and the date on its card. Where the licence allows it, you read the whole book here, with its authors credited on every page. The others are listed with their source, and we are asking their publisher for permission to bring them in.

Mathematics
Information technology
Physics
Chemistry
Biology
Mathematicsupdated August 2026
Matthew Boelkins, David Austin, Steven Schlicker
Mathematicsupdated December 2024
David M Diez, Mine Çetinkaya-Rundel, Christopher D Barr
Mathematics2016
Gilbert Strang, Edwin “Jed” Herman
Source: openstax.org/details/books/calculus-volume-1. Its licence doesn't allow a paid platform to show it, so WorldClass cites it and doesn't copy it.
Mathematics2023
Barbara Illowsky, Susan Dean
Source: openstax.org/details/books/introductory-statistics-2e. Its licence doesn't allow a paid platform to show it, so WorldClass cites it and doesn't copy it.
Mathematics2021
Jay Abramson and contributing authors
Source: openstax.org/details/books/algebra-and-trigonometry-2e. Its licence doesn't allow a paid platform to show it, so WorldClass cites it and doesn't copy it.
Information technologyupdated November 2020
Swaroop C H
Information technology2024
Udayan Das, Aubrey Lawson, Chris Mayfield, Narges Norouzi
Source: openstax.org/details/books/introduction-python-programming. Its licence doesn't allow a paid platform to show it, so WorldClass cites it and doesn't copy it.
Physics2022
Paul Peter Urone, Roger Hinrichs
Source: openstax.org/details/books/college-physics-2e. Its licence doesn't allow a paid platform to show it, so WorldClass cites it and doesn't copy it.
Chemistry2019
Paul Flowers, Klaus Theopold, Richard Langley, William R. Robinson
Source: openstax.org/details/books/chemistry-2e. Its licence doesn't allow a paid platform to show it, so WorldClass cites it and doesn't copy it.
Biology2018
Mary Ann Clark, Jung Choi, Matthew Douglas
Source: openstax.org/details/books/biology-2e. Its licence doesn't allow a paid platform to show it, so WorldClass cites it and doesn't copy it.
The books' authors and publishers (OpenStax, part of Rice University, and LibreTexts) are not affiliated with Flash and don't endorse it.
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