This collection originally published: Garden City, N.Y. : Doubleday, 1966 ; London : Gollancz, 1967.
Contents: The three-cornered wheel - A sun invisible - The trouble twisters - 'These stories originally appeared, in a somewhat different form in "Analog Science Fact & Science Fiction", "The trouble twisters" under the title of "Trade team" - title page verso.
The trouble twisters by Poul Anderson. ISBN 0586028714. Published by Panther in 1974. Publication and catalogue information, links to buy online and reader comments.