It would be interesting to compile these in one place.
The 2006 translation of the Gospel of Judas was interesting.
“However, it is argued that a closer reading of the existent text, as presented in October 2006, shows Christianity in a new light. According to Elaine Pagels, for instance, Judas is portrayed as having a mission to hand Jesus over to the soldiers. She says that Bible translators have mistranslated the Greek word for “handing over” to “betrayal”.”
They are still in the old Catholic Reims-Douay Bible in their original places. The RSV Catholic Bible has them, as well. The Ignatius and Oxford editions of the RSV have them. They are not banned, nor are they "hidden knowledge." They are simply books of the Bible that were removed at some point in the much more recent past.