You can purchase the Revised and Expanded Edition (2009) from retailers like Amazon or view select translations at the Gnosis Society Library . The Gnostic Bible: Revised and Expanded Edition
Edited by Willis Barnstone and Marvin Meyer, The Gnostic Bible: Gnostic Texts of Mystical Wisdom from the Ancient and Medieval Worlds is an extensive 880-page collection covering 1,300 years of diverse spiritual traditions. The anthology gathers texts from Sethian, Valentinian, Hermetic, Mandaean, Manichaean, and later Cathar and Islamic expressions, focusing on gnostic knowledge.