@book {wilson_systems:_1990,
	title = {Systems: concepts, methodologies and applications},
	year = {1990},
	note = {n/a},
	publisher = {Wiley},
	organization = {Wiley},
	edition = {2nd},
	address = {Chichester},
	abstract = {<p>explains checkland{\textquoteright}s method</p>
},
	author = {Wilson, Brian}
}
