Cassingham KM, Sills EO, Pattanayak SK, Mansfield CA. Voluntary conservation of North Carolina's natural heritage. J For. 2002;100(5):16-23.
Webster AJ, Saville C, Church BM, Gnanasakthy A, Moss R. Some effects of different rearing systems on health, cleanliness and injury in calves. Vet J. 1985 Sep;141(5):472-83.
Webster AJ, Saville C, Church BM, Gnanasakthy A, Moss R. The effect of different rearing systems on the development of calf behaviour. Vet J. 1985 May;141(3):249-64.