Notes
In 1952, 'Guardian angel' was expanded to become part 1 'Earth and the Overlords' of the novel Childhood's End. According to a note in "Collected Stories" James Blish added a new ending after the story was rejected multiple times.
Publications (31)
| Date | Publication | Publisher | Type | Page |
|---|---|---|---|---|
| 1950 | New Worlds, Winter 1950 | Nova Publications Ltd. | MAGAZINE | 2 |
| April 1950 | Famous Fantastic Mysteries, April 1950 | All-Fiction Field, Inc. | MAGAZINE | 98 |
| April 1950 | Famous Fantastic Mysteries, April 1950 | All-Fiction Field, Inc. (Canada) | MAGAZINE | 98 |
| December 1980 | Science Fiction Origins | Fawcett Popular Library | Anthology | 282 |
| November 1983 | The Sentinel | Berkley Books | Collection | 51 |
| January 1984 | The Sentinel | Berkley Books | Collection | |
| March 1984 | The Sentinel | Berkley Books / SFBC | Collection | 25 |
| 1985 | The Sentinel | Panther / Granada | Collection | |
| December 1986 | The Sentinel | Berkley Books | Collection | 39 |
| June 1987 | Devils | Signet / New American Library | Anthology | 265 |
| 1989 | Devils | Robinson | Anthology | |
| August 1991 | Famous Fantastic Mysteries | Gramercy Books | Anthology | 340 |
| September 1991 | The Sentinel | Grafton | Collection | [56] |
| 1993 | The Sentinel | HarperCollins | Collection | 55 |
| April 1996 | The Sentinel | Barnes & Noble Books | Collection | |3 |
| 2000 | The Collected Stories | Gollancz / Orion | Collection | 203 |
| September 2000 | The Sentinel | ibooks | Collection | 51 |
| September 2000 | The Sentinel | Voyager / HarperCollins | Collection | 57 |
| February 2001 | The Collected Stories of Arthur C. Clarke | Tor | Collection | 203 |
| February 2001 | The Collected Stories of Arthur C. Clarke | Tor / SFBC | Collection | 203 |
| October 2001 | The Collected Stories of Arthur C. Clarke | Gollancz / Orion | Collection | 203 |
| January 2002 | The Collected Stories of Arthur C. Clarke | Orb | Collection | 203 |
| August 2002 | The Sentinel | ibooks | Collection | |51 |
| November 2008 | The Collected Stories of Arthur C. Clarke | Paw Prints | Collection | 203 |
| October 2010 | The Collected Stories: Volume Two | Clipper / W. F. Howes | Collection | |203 |
| June 2011 | The Collected Stories of Arthur C. Clarke | Gollancz / Orion | Collection | |203 |
| November 2012 | History Lesson | RosettaBooks | Collection | |203 |
| 2016 | The Collected Stories of Arthur C. Clarke | RosettaBooks | Collection | |
| August 2016 | The Collected Stories of Arthur C. Clarke | Audible Studios | Collection | |203 |
| October 2019 | Childhood's End | Centipede Press | Novel | 305 |
| April 2022 | Arthur C. Clarke Audiobook Collection | MotionAudiobooks | Omnibus | |143 |