Jan Berenstain; Mike Berenstain. (2009). The Berenstain Bears' Class Trip (I Can Read Level 1). HarperCollins.
Chicago Style (17. basım) AtıfJan Berenstain; Mike Berenstain. The Berenstain Bears' Class Trip (I Can Read Level 1). HarperCollins, 2009.
MLA (9th ed.) AtıfJan Berenstain; Mike Berenstain. The Berenstain Bears' Class Trip (I Can Read Level 1). HarperCollins, 2009.
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