Pathfinder - Sourcebook Abbreviations Guide
Affiliate Link Disclaimer: Some of the links below are "affiliate links". To learn more about affiliate links on RPGBOT.net, please see the RPGBOT FAQ.
While the books are all available online via Amazon and other retailers, I ask that you please support your friendly local game store. If you choose to purchase sourcebooks through amazon (and I can't blame you; they're almost always on sale somehow), I encourage you to use smile.amazon.com, which allows you to donate a portion of the price of your purchases to a charity of your choice.