1. Appel MJG (1969) Am J Vet Res 30:1167–1182
2. Appel MJG, Gillespie JH (1972) Virol Monogr 11:1–96
3. Appel MJG, Gibbs PJ, Martin SJ, ter Meulen V, Rima BK, Stephenson JR, Taylor WP (1981) In: Kurstak E, Kurstak C (eds) Comparative diagnosis of viral diseases, vol IV. Academic, London, pp 235–297
4. Billter MA, ter Meulen Curr Top Microbiol Immunol 191:1–196
5. Griffin DE, Bellini WJ (1996) In: Fields BN et al (eds) Field’s virology, 3rd edn. Lippincott-Raven Publishers, Philadelphia, pp 1267–1312