Headland, T. N. (1986). Why foragers do not become farmers: A historical study of changing ecosystem and its effect on a Negrito hunter-gatherer group in the Philippines. UMI Dissertation Services.
Dyfyniad Arddull ChicagoHeadland, Thomas N. Why Foragers Do Not Become Farmers: A Historical Study of Changing Ecosystem and Its Effect on a Negrito Hunter-gatherer Group in the Philippines. Ann Arbor, Mich: UMI Dissertation Services, 1986.
Dyfyniad MLAHeadland, Thomas N. Why Foragers Do Not Become Farmers: A Historical Study of Changing Ecosystem and Its Effect on a Negrito Hunter-gatherer Group in the Philippines. UMI Dissertation Services, 1986.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.