@unpublished{Blundell2005,
author = {Richard Blundell and Martin Browning and Ian Crawford},
title = {Best nonparametric bounds on demand responses},
year = {2005},
month = {Oct},
volume = {pp.},
doi = {10.1920/wp.ifs.2005.0520},
issn = {1742-0415},
url = {http://cemmap.ifs.org.uk/wps/cwp1205.pdf},
}