1. Mitsch WJ, Mitsch RH, Turner RE (1994) Wetlands of the old and new worlds: ecology and management. In: Mitsch WJ (ed) Global wetlands: old world and new. Elsevier Science, Amsterdam, pp 3–56
2. Maltby E, Turner GE (1983) Wetlands of the world. Geogr Mag 55:12–17
3. Matthews E, Fung I (1987) Methane emission from natural wetlands: global distribution, area, and environmental characteristics of sources. Glob Biogeochem Cycles 1:61–86
4. Aselman I, Crutzen PJ (1989) Global distribution of natural freshwater wetlands and rice paddies, their net primary productivity, seasonality and possible methane emissions. J Atmos Chem 8:307–358
5. Aselman I, Crutzen PJ (1990) A global inventory of wetland distribution and seasonality, net primary productivity, and estimated methane emissions. In: Bouwman AF (ed) Soils and the greenhouse effect. Wiley, New York, pp 441–449