@book {3994,
	title = {Variability of Phragmites australis (Cav.) Trin Ex Steudel},
	year = {1972},
	publisher = {Rijksuniversiteit te Groningen},
	organization = {Rijksuniversiteit te Groningen},
	address = {Leiden},
	keywords = {PHRAGMITES, Phragmites australis},
	author = {van den Toorn, Jan}
}
