@article{Carus2009,
author = {Carus, A.W. and Ogilvie, S.},
title= {Turning qualitative into quantitative evidence: A well-used method made explicit},
year = {2009},
doi = {10.1111/j.1468-0289.2009.00486.x},
journal = {Economic History Review},
volume = {62},
number = {4},
pages = {893−925},
}