A book was published some decades ago, about steam locos in eastern Europe ("past and present" thereof, as at that date). Overall judgment of it by readers, was that it contained much useful and interesting stuff; but was marred by seemingly having been rather hastily slapped together -- compounded by dodgy proofreading. At one point there were mentioned within a few lines of text, the regions of Slovenia, Slovania, and Slavonia. One of those: in fact doesn't exist in real life, and never has. Which one?