HTML ebook; also available, minus illustrations & page numbers, as plain text (us-ascii); all available from Ebook #23198.
Transcribed from Analog, February 1963.
HTML edition includes artwork, credited to Schelling, from that issue, & marginal page numbers from that issue running 115-129.
The publisher's metadata gives the author as "Gordon Randall Garrett (AKA David Gordon)", but the text itself gives the name David Gordon.
A note before the text says: "Produced by Louise Hope, Greg Weeks and the Online Distributed Proofreading Team at http://www.pgdp.net".