I have a book, first published in 1987, by Roger Black (ISBN 0-7181-2842-7) entitled "Getting Things Done" with a subtitle "A Radical New Approach to Managing Time and Achieving More at Work".
Does David Allen's work/book predate this? The earliest reference to David Allen's book I have found to date is 2001. I ask because Roger Black's book describes, for example, a very similar system for dealing with the "in-tray".
Just curious and interested.