Here are links to the print editions of the official S&W rulebooks:
Swords & Wizardry White Box Rules (softcover)
Swords & Wizardry White Box Rules (hardcover)
Swords & Wizardry Core Rules (softcover)
Swords & Wizardry Core Rules (hardcover)
Swords & Wizardry Complete Rules (hardcover)
and White Box Fantastic Medieval Adventure Game (FMAG) in Print