Não informado. (1979). Focus on Learning Problems in Mathematics. Center for Teaching Learning on Mathematics.
Chicago-Zitierstil (17. Ausg.)Não informado. Focus on Learning Problems in Mathematics. Framingham, Mass: Center for Teaching Learning on Mathematics, 1979.
MLA-Zitierstil (8. Ausg.)Não informado. Focus on Learning Problems in Mathematics. Center for Teaching Learning on Mathematics, 1979.
Achtung: Diese Zitate sind unter Umständen nicht zu 100% korrekt.