Cremer, Helmuth, Roy, Bernard, Toledano, Joëlle and de Villemeur, Étienne (2005) Worksharing, Pricing and Competition in the Postal Sector. In: Regulatory and Economics Challenges in the Postal and Delivery Sector Crew, Michael A. and Kleindorfer, Paul R. (eds.) Springer. Series “Topics in Regulatory Economics and Policy” pp. 139-161. ISBN 978-0-387-23637-7