* 78/xx/xx    1 Psychohistory and Encyclopedia
* 78/xx/xx    2 Maze The
* 78/xx/xx    3 The Merchant Princess
* 78/xx/xx    4 The General
* 78/xx/xx    5 The Mule
* 78/xx/xx    6 Flight from the Mule
* 78/xx/xx    7 The Mule Finds
* 78/xx/xx    8 Star's End