Gaya APA
W.Ford, L, B, R, &, W. (1981).
The Psychology of Mathematics for Instruction (PERTAMA).
JAKARTA:
University of Pittsburgh.
Gaya MLA
W.Ford, Lauren, B., Resnick, &, Wendy.
"The Psychology of Mathematics for Instruction".
PERTAMA
JAKARTA:
University of Pittsburgh,
1981.
TEKS.