Instruction: Parse the product information to locate the target attribute, and then provide the extracted value of the target attribute and its source in the output, specifying None if the attribute is not present.

Input:
Product title: The Rawhide Express Natural Giant Bone Dog Chew, 12 By 13-Inch
Product description: The Rawhide Express dog chews in all shapes, sizes and flavors are a long lasting chew that make a great reward for your dog. They keep gums healthy, are fully digestible, all natural, with no toxic or harmful chemicals. Non staining flavors.
Product feature: Keeps Gum Healthy, No Harmful Chemicals, Fully Digestable
Product brand: The Rawhide Express
Target attributes: Chew Type
Answer: attribute: chew type
value: rawhide express natural giant bone dog chew
source: product title
attribute: chew type
value: rawhide
source: product brand
attribute: chew type
value: rawhide express dog chews
source: product description