@inbook{Sobek2006,
author = {Sobek, M. },
title= {Occupations},
year = {2006},
editor = {Carter, S.B.},
editor = {Gartner, S.S.},
editor = {Haines, M.R.},
editor = {Olmstead, A.L.},
editor = {Sutch, R.},
editor = {Wright, G. },
booktitle = {Historical statistics of the United States: Earliest times to the present},
address = {Cambridge},
publisher = {Cambridge University Press},
pages = {35--40},
}