Heddens, J. W. (1974). Today's mathematics: A guide to concepts and methods in elementary school mathematics (3d ed.). Science Research Associates.
Citación estilo ChicagoHeddens, James W. Today's Mathematics: A Guide to Concepts and Methods in Elementary School Mathematics. 3d ed. Chicago: Science Research Associates, 1974.
Cita MLAHeddens, James W. Today's Mathematics: A Guide to Concepts and Methods in Elementary School Mathematics. 3d ed. Science Research Associates, 1974.
Warning: These citations may not always be 100% accurate.