Gaya APA
Swanson, C, P., Poyla, G. (1962).
Mathematical discovery vol I on understanding, learning, and teaching ì problem solving .
New York:
.
Gaya MLA
Swanson, Carl, P.., Poyla, George.
"Mathematical discovery vol I on understanding, learning, and teaching ì problem solving".
New York:
,
1962.
Text.