@book {trehane1989index,
	title = {Index Hortensis: Perennials},
	series = {Index Hortensis: Including Border Plants, Herbs, Bulbous Plants, Non-woody Alpines, Aquatic Plants, Outdoor Ferns and Ornamental Grasses : a Modern Nomenclator for Botanists, Horticulturists, Plantsmen, and the Serious Gardener. Perennials},
	year = {1989},
	publisher = {Quarterjack},
	organization = {Quarterjack},
	abstract = {<p>This compact volume includes all perennial plant names found in some 2800 nursery catalogs issued in northern Europe from 1984 to 1987</p>
},
	isbn = {9780948117008},
	url = {http://books.google.co.uk/books?id=vtBGAAAAYAAJ},
	author = {P Trehane}
}
