@book{164751,
	author = {Symposium Sponsored by Western Regional Coordinating Committe on Range Economics. (42 : 1989 : Billings , Montana)},
	title = {Multiple users-multiple products  /},
	publisher = { :,},
	year = {1989},
	address = {Billing, Mon.  :},
	note = {Fotocopía}
}