Haurongo: Popper, Karl Raimund
He whakaaturanga anō
Rārangi pukapuka
Obit. The Times. 19 Sept. 1994: 21
Schilpp, P. A., ed. The philosophy of Karl Popper. 2 vols. La Salle, 1974
Strauss, H. A. & W. Röder, eds. International biographical dictionary of Central European émigrés, 1933--1945. Vol. 2, part 2. Munich, 1983
Sutherland, O.R.W. Paikea: the life of I.L.G. Sutherland. Christchurch, 2013