Complex sentence: To account for these apparent discrepancies, the "Season 6B" theory was proposed, first documented in the 1995 book "The Discontinuity Guide", by Paul Cornell, Martin Day and Keith Topping.
Split into simpler sentences: To account for these apparent discrepancies, the "Season 6B" theory was proposed. This was first documented in the 1995 book "The Discontinuity Guide", by Paul Cornell, Martin Day and Keith Topping.