What is similar and unique to passage: Matthew 12:38-42; Mark 8:11-13; Luke 11:29-32?
There is so much to say. In light of this, I will limit my answer to three points.
First, from a general point of view, we are dealing with the synoptic problem. Matthew, Mark and Luke are very similar and there seems to be borrowing from each other. According to the most famous view, Mark is the earliest gospel and there is a document called, "Q," which all the gospels used as well.
Second, the biggest similarity is in the area of theme. The religious teachers of Jesus' day want more proof or evidence of who Jesus is. They want signs and wonders to confirm his identity. The irony is that Jesus has been giving signs all along. In light of this, Jesus states that he will give no more signs other than the sign of Jonah - Matthew and Luke.
Third, the difference is in details. For example, Matthew and Luke mention the sign of Jonah, but Mark does not mention the sign of Jonah at all. Part of the reason for this is due to the shortness of Mark. Also Matthew and Luke make reference to the Queen of the South and the men of Nineveh.