@inbook{Malthus1986,
author = {Malthus, T.R.},
title= {An essay on the principle of population (1798)},
year = {1986},
editor = {Wrigley, E.A.},
editor = {Souden, D.},
booktitle = {The Works of Thomas Robert Malthus},
address = {London},
publisher = {William Pickering},
series = {Vol 1},
}