@article {Buckle:1 April 2004:1470-8272:393,
	author = "Buckle, David",
	title = "How to calculate breadth: An evolution of the fundamental law of active portfolio management",
	journal = "Journal of Asset Management",
	volume = "4",
	year = "1 April 2004",
	abstract = "Grinold and Kahn's highly acclaimed fundamental law of active management has as a weak point the lack of a measurable definition of breadth. Buckle (2003) developed a more general model of active portfolio management that uses fewer assumptions than Grinold and Kahn, resulting in the generalised fundamental law of active management. This law unfortunately has quite a complex mathematical representation. By applying some of Grinold and Kahn's assumptions to this generalised law, however, one derives a semi-generalised law, which is identical in form to Grinold and Kahn's original law, but with a measurable definition of breadth. The simplicity of application of this semi-generalised law is illustrated in several worked examples.Journal of Asset Management (2004) 4, 393-405; doi:10.1057/palgrave.jam.2240118",
	pages = "393-405(13)",
	url = "http://www.ingentaconnect.com/content/pal/jam/2004/00000004/00000006/art00003"
	doi = "doi:10.1057/palgrave.jam.2240118"
}