Did Azamov steal this?
You can't steal "Flatland". It's a bit too well known. I read it in high school fourty years ago.
Not that I know of. Here is Azimov, writing a forward to a collection of two of Abbott's works ...
February 1994 : Paperback TopTitle: Flatland : The Classic Speculation On Life In Four Dimensions/Sphereland : A Continuing Speculation On An Expanding Universe/2 Books in 1 Volume (Everyday Handbook)
Author(s): Edwin A. Abbott, Dionys Burger, Foreword by Isaac Asimov
ISBN: 0062732765
Publisher: HarperCollins Publishershttp://books.fantasticfiction.co.uk/c0/c3170.htm?authorid=3907 <-- Link