pb?Paperback. Typically 7" by 4.25" (18 cm by 11 cm) or smaller, though trimming errors can cause them to sometimes be slightly (less than 1/4 extra inch) taller or wider/deeper.
Notes: $9.99 Canada. Patterson introduction states that Heinlein added 10,000 words to the 1941 Astounding serial for the Gnome edition. Signet changed the title to "The Day After Tomorrow" in 1951 because the fifth column reference was considered dated. This edition restores the original title.