Cazals, Catherine, Duchemin, Pascale, Florens, Jean-Pierre, Roy, Bernard and Vialaneix, Olivier (2002) An Econometric Study of Cost Elasticity in the Activities of Post Office Counters. In: Postal and Delivery Services: Pricing, Productivity, Regulation and Strategy Springer. Series “Topics in Regulatory Economics and Policy”, Vol. 41. pp. 161-170. ISBN 978-0-7923-7638-5