Free images results:

Backpack pictures, stock photos and images


Towerhouse Stock Image
Author: Tamas
Solitude Stock Photo
Author: Cjashar

Also, here are some commercial RF-licensed images that match your search criteria:  
Backpack Royalty Free Stock Image
Author: Coprid

Explore more commercial options: More Backpack Stock Illustrations & Vectors | More Backpack Stock Video Footage