Is demand for market dominant products of the United States Postal Service becoming more own price elastic?

Bozzo, T., Capogrossi, K., Eakin, K., Pickett, J., & Srinivasan, M. (2014). Is demand for market dominant products of the United States Postal Service becoming more own price elastic? In The role of postal service in a digital age (pp. 28 - 45). Edward Elgar.