Complex sentence: Perhaps because its subject matter now seems quite dated, "The Serial" has been out of print for several years in the United States but was reprinted in the United Kingdom by Prion Humour Classics in 2000.
Split into simpler sentences: Perhaps because its subject matter is no longer the present or recent past, "The Serial" has been out of print for several years in the United States. It was reprinted in the United Kingdom by Prion Humour Classics in 2000.