(1970). Teaching mathematics in the elementary school: What's needed? What's happening? National Assoc. of Elementary School Principals.
Chicago-Zitierstil (17. Ausg.)Teaching Mathematics in the Elementary School: What's Needed? What's Happening? Washington, DC: National Assoc. of Elementary School Principals, 1970.
MLA-Zitierstil (9. Ausg.)Teaching Mathematics in the Elementary School: What's Needed? What's Happening? National Assoc. of Elementary School Principals, 1970.
Achtung: Diese Zitate sind unter Umständen nicht zu 100% korrekt.