International correspondenceFreudenthal, Hans; Leatherman, G.H.; Källqvist, Hans · The Journal of the American Dental Association · 1960

Book reviewsC. Jager; James B. Hartle; H. W. Drawin; R. G. Giovanelli; Hans Freudenthal; H. Wittenberg; Cornelius A. Tobias; H. Laan; J. A. Smit · 1974

Oktaven, Ausnahmegruppen und OktavengeometrieHans Freudenthal · Geometriae Dedicata · 1985

CreativityHans Freudenthal · Educational Studies in Mathematics · 1977

Bastiaan's experiments on Archimedes' principleHans Freudenthal · Educational Studies in Mathematics · 1977

Pupils' achievements internationally compared — The IEAHans Freudenthal · Educational Studies in Mathematics · 1975

Book reviewsHans Freudenthal; Konrad Jacobs; Paulo Abrantes · Educational Studies in Mathematics · 1986

Major problems of mathematics educationHans Freudenthal · Educational Studies in Mathematics · 1981

Ridder J.. Einige Anwendungen des Dualitätsprinzips in topologischen Strukturen. Koninklijke Nederlandsche Akademie van Wetenschappen, Proceedings of the section of sciences, vol. 50 (1947), pp. 731–740; also Indagationes mathematicae, vol. 9 (1947), pp. 341–350.The Journal of Symbolic Logic · 1948

van Rootselaar B.. Die Struktur der rekursiven Wortarithmetik des Herrn V. Vučković. Koninklijke Nederlandse Akademie van Wetenschappen, Proceedings, series A, Bd. 65 (1962), S, 192–200; auch Indagationes mathematicae, Bd. 24 (1962), S. 192–200.Hermes, H. · The Journal of Symbolic Logic · 1964

Martin Norman M.. Some analogues of the Sheffer stroke function in n-valued logic. Koninklijke Nederlandse Akademie van Wetenschappen, Proceedings of the section of sciences, vol. 53 (1950), pp. 1100–1107; also Indagationes mathematicae, vol. 12 (1950), pp. 393–400.Rose, Alan · The Journal of Symbolic Logic · 1951

Certain Simple, Unsolvable Problems of Group Theory. I1)1)Unless otherwise indicated, the results and proofs of this and subsequent related papers are as given (in somewhat more detail) in Several simple unsolvable problems of group theory related to the word problem, a doctoral dissertation accepted by Princeton University in April, 1952. The proof of the unsolvability of the quasi-MAGNUS problem was presented to a meeting of The Association for Symbolic Logic, April 28, 1951. (Abstract, Journal of Symbolic Logic, 16, 237.)Our thanks are due to Professors Alonzo Church and Roger Lyndon for their constructive suggestions regarding this dissertation; to Professor Wilhelm Magnus, for stimulating discussions regarding possible extensions.Boone, William W. · Indagationes Mathematicae (Proceedings) · 1954