@article{Freedman1997,
author = {Judith Freedman and Emma Chamberlain},
title = {Horizontal equity and the taxation of employed and self-employed workers },
journal = {Fiscal Studies},
year = {1997},
month = {Feb},
volume = {18},
number = {1},
pages = {87–118},
issn = {Print: 0143-5671 Online: 1475-5890},
url = {http://www.ifs.org.uk/fs/articles/fsfreed1.pdf},
}