add external source - Amazon

• https://stackoverflow.com/questions/4589813/amazon-book-api-for-python-or-ruby

resources:

• https://pypi.org/project/python-amazon-simple-product-api/ (Last released: Feb 24, 2017)
• https://pypi.org/project/python-amazon-product-api/ (Last released: Mar 30, 2014)