Sharp, P., & Weisdorf, J. (2007). From preventive to permissive checks: The changing nature of the Malthusian relationship between nuptiality and the price of provisions in the nineteenth century. University of Oxford.
Lua i Stíl Chicago (17ú heag.)Sharp, P., agus J. Weisdorf. From Preventive to Permissive Checks: The Changing Nature of the Malthusian Relationship Between Nuptiality and the Price of Provisions in the Nineteenth Century. University of Oxford, 2007.
Lua MLA (9ú heag.)Sharp, P., agus J. Weisdorf. From Preventive to Permissive Checks: The Changing Nature of the Malthusian Relationship Between Nuptiality and the Price of Provisions in the Nineteenth Century. University of Oxford, 2007.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.