This Bible contradiction is from the Skeptic's Annotated Bible.
Acts 1:1-2 View context
The former treatise have I made, O Theophilus, of all that Jesus began both to do and teach,
Until the day in which he was taken up, after that he through the Holy Ghost had given commandments unto the apostles whom he had chosen:
John 21:25 View context
And there are also many other things which Jesus did, the which, if they should be written every one, I suppose that even the world itself could not contain the books that should be written. Amen.