1. Haase AT. Pathogenesis of lentivirus infections. Nature. 1986; 322: 130–136.
2. Narayan O, Clements JE. Biology and pathogenesis of lentiviruses. J Gen Virol. 1989; 70:1617–1639.
3. Crawford TB, Adams DS, Cheevers WP, Cork LC. Chronic arthritis in goats caused by a retrovirus. Science. 1980; 207: 997–999.
4. Oliver RE, Gorham JR, Parish SF et al. Ovine progressive pneumonia: Pathologic and virologic studies on the naturally occurring disease. Am J Vet Res. 1982; 42: 1554–1559.
5. Oliver RE, Gorham JR, Perryman LE, Spencer GR (1982). Ovine progressive pneumonia: Experimental intrathoracic, intracerebral, and intra-articular infections. Am J Vet Res. 1982; 42: 1560–1564.