Placement
- contained in Admiraltycollection
- contained in Black Holes and Other Marvelsanthology
- contained in Explorers of Spaceanthology
- contained in Going for Infinitycollection
- contained in Space Pioneersanthology
- contained in The Best of Omni Science Fiction No. 6anthology
- contained in The Best of Poul Andersoncollection
- contained in The Norton Book of Science Fiction: North American Science Fiction, 1960-1990anthology
- contained in World's Best Science Fiction: 1969anthology