Cover art
Moore, Alan, and Dave Gibbons. Watchmen, issue #1. DC Comics 1987.

Moore, Alan, and Dave Gibbons. Watchmen
Divergence: 1939 CE
What if: Costumed vigilantes appeared in 1939 and a real superhero with superpowers was created in 1959 by an accident in a nuclear research lab.
Summary: In 1986, Nixon is still president, someone is killing old costumed heroes and nuclear war looks imminent. Why are the latter two related?
Published: Twelve-issue comic book series, DC Comics 1986-87.
Published: In one volume, DC Comics 1987 (0930289234BUY), 1995 (0930289234BUY), 2008 (1401219268BUY), 2014 (1401245250BUY); Warner 1987 (0446386898).
Original in: English.
Translation: Danish by Niels Søndergaard as Vogterne, six-issue comic book series, Interpresse 1989.
Translation: French by Jean-Patrick Manchette as Les Gardiens, six-issue comic book series Zenda 1987-88. Published in one volume by Zenda 1992 (2876871378), in two volumes by Zenda 1992 (2876871335, 2876871343), and in one volume as Watchmen les gardiens by Delcourt 1998 (2840552515).
Translation: Swedish by Göran Ribe and Horst Schröder as Watchmen, Medusa 1990 (9170890099).

Moore, Alan, Dave Gibbons, and Leslie S. Klinger. Watchmen: The Annotated Edition
Divergence: 1939 CE
Published: DC Comics 2017 (1401265561BUY).