APA Style
Gray, Cara. ().
Simple machines .
New York:
Scholastic.
Chicago Style
Gray, Cara.
Simple machines.
New York:
Scholastic,
.
Text.
MLA Style
Gray, Cara.
Simple machines.
New York:
Scholastic,
.
Text.
Turabian Style
Gray, Cara.
Simple machines.
New York:
Scholastic,
.
Print.