A web version and PDF version of our freely available, open source textbook can be found here: openstax.org/details/psychology
If you prefer, you can also get a print version at a low cost. The official print version is only available at the US version of Amazon.com but will ship here: https://www.amazon.com/Psychology-OpenStax-hardcover-version-color-dp-1975076451/dp/1975076451/