@inbook{inbookc020d7c0,
title   = {Play in hunter-gatherer society},
author = {Gosso, Yumi and Otta, Emma and Morais, Maria de Lima Salum and Ribeiro, Fernando José Leite and Bussab, Vera Silvia Raad},
year = {2005},
publisher = {Guilford Press},
journal   = {The nature of play: great apes and humans}
}