Gaya APA
Herrera, M., PInkley, D.
(2009).
Backpack 4
(
second edition)
.
New York:
Pearson Longman.
Gaya MLA
Herrera, Mario., PInkley, Diane.
"Backpack 4".
second edition
New York:
Pearson Longman,
2009.
Text.