@book {2457,
	title = {A Sacred Unity. Further Steps to an Ecology of Mind},
	year = {1991},
	publisher = {Harpers Collins},
	organization = {Harpers Collins},
	address = {New York},
	author = {Bateson, Gregory}
}
@book {2451,
	title = {Steps to an Ecology of Mind},
	year = {1972},
	publisher = {Ballantine Books},
	organization = {Ballantine Books},
	address = {New York},
	author = {Bateson, Gregory}
}
