Acts of the Apostles
Most people think that the author of Acts also wrote the Gospel of Luke, as Acts 1:1 refers to 'the former treatise have I made, Theophilus, of all that Jesus began both to do and teach'. The traditional view is that both the two books were written c. 60 by a companion of Paul named Luke. Many theologians still think so. But some think the books were written by an unknown author at a later date, sometime between 80 and 150.