1. Alexander M (1971) ‘Microbial ecology.’ (John Wiley & Sons: New York)
2. Allsopp D, Colwell RR, Hawksworth DL (1995) (eds) ‘Microbial diversity and ecosystem function.’ (CAB International: Wallingford)
3. Andrews JH, Harris RF (2000) The ecology and biogeography of microorganisms on plant surfaces. Annual Review of Phytopathology 38, 145–180.
4. Angiosperm Phylogeny Group (APG) (1998) An ordinal classification for the families of the flowering plants. Annals of the Missouri Botanical Garden 85, 532–553.
5. Anonymous (2000) ‘Gran Canaria declaration.’ (Botanic Gardens Conservation International: Kew)