"One day (a) reporter for the Paris Soir visited the Berlin Zoo...standing outside the spacious cage housing the newly-acquired Brecht Biped, Fritz, when the world seemed to lurch...Then he was no longer outside the cage looking in, but inside looking out...
Used availability for Damon Knight's Mind Switch
November 1966 : UK Hardback
1968 : UK Paperback
September 2011 : Australia, UK Kindle edition