Brand, G. The Material Apriori and the Foundation for its Analysis in Husserl: Gerd Brand. The later Husserl and the idea of phenomenology : idealism - realism, historicity and nature ; papers and debate of the International Phenomenological Conference, held at the University of Waterloo, Canada, April 9 - 14, 1969.(1972).

Brand, Gerd. "The Material Apriori and the Foundation for Its Analysis in Husserl: Gerd Brand." The Later Husserl and the Idea of Phenomenology : Idealism - Realism, Historicity and Nature ; Papers and Debate of the International Phenomenological Conference, Held at the University of Waterloo, Canada, April 9 - 14, 1969.(1972) .

Brand, Gerd. "The Material Apriori and the Foundation for Its Analysis in Husserl: Gerd Brand." The Later Husserl and the Idea of Phenomenology : Idealism - Realism, Historicity and Nature ; Papers and Debate of the International Phenomenological Conference, Held at the University of Waterloo, Canada, April 9 - 14, 1969.(1972), .