Paul Keegan.How David Allen mastered getting things done.The management guru has learned to relax, go with the flow, and market his mysterious elixir of success(англ.)(недаступная спасылка).CNNMoney, Business 2.0 Magazine(21 ліпеня 2007).Архівавана з першакрыніцы 23 снежня 2015.Праверана 22снежня 2015.
Paul Keegan.How David Allen mastered getting things done.The management guru has learned to relax, go with the flow, and market his mysterious elixir of success(англ.)(недаступная спасылка).CNNMoney, Business 2.0 Magazine(21 ліпеня 2007).Архівавана з першакрыніцы 23 снежня 2015.Праверана 22снежня 2015.