@unpublished{Adam2007,
author = {Stuart Adam and Glen Loutzenhiser},
title = {Integrating Income Tax and National Insurance: an interim report},
year = {2007},
month = {Dec},
doi = {10.1920/wp.ifs.2007.0721},
issn = {1742-0415},
url = {http://www.ifs.org.uk/wps/wp2107.pdf},
}