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: Dr Koffer Larry Venetian Leather Flapover Laptop Briefcase
Product description: Extremely handsome and well featured double gusset brief. Everything is well thought out and convenient. A pleasure to carry and use.
Product feature: Leather, 10.5" high, 15" wide, Dimensions: 11" x 16" x 4.5", Features of this item include: Business, Leather, Product Dimensions: 4.5 x 15 x 10.5 inches, Shipping Weight: 6 pounds, ASIN: B000X5OEAE, Item model number: DKMB003-02-04, Date first listed on Amazon: March 6, 2004, Average Customer Review: 5.0 out of 5 stars 1 customer review
Product brand: Dr. Koffer
Target attributes: Material
Answer: attribute: material
value: leather
source: product title
attribute: material
value: leather
source: product feature