The Singular Visitor from Not-Yet by John Sladek “The Singular Visitor from Not-Yet” by John Sladek, Playboy, June 1968.
Getting There Is (n-1/n)th the Fun by John Sladek “Getting There Is (n-1/n)th the Fun” by John Sladek, in The New Improved Sun, edited by Thomas M. Disch (Harper and Row, September 1975).