The internal rate of return of an investment
In: Applications and Modelling in Learning and Teaching Mathematics, Jg. 1989, S. 195-200
Mathematics teachers should have the conviction that every individual should be taught mathematics
In: A collection of papers on pre-service teacher education, Jg. 1985, S. 105-109The teaching of geometry
In: Zentralblatt für Didaktik der Mathematik, Jg. 1985, S. 54-55Will Logo environments really improve education?
In: Mathematiques pour tous ä I'age de I'ordinateur. Compte rendu de la 37e rencontre internationale de la CIEAEM a Lerden 1985, Jg. 1986, S. 336-342