How many books are in Isaac Asimov's Foundation series?
7
Q1564644
entity
Foundation series
Foundation
Q34981
entity
Isaac Asimov
Isaac Asimov's
Q753894
Foundation
Q839800
Foundation and Empire
Q853927
Second Foundation
Q932592
Foundation’s Edge
Q1050014
Foundation and Earth
Q783533
Prelude to Foundation
Q938629
Forward the Foundation