@article{ferrante2004,
	author="A. Ferrante",
	title="On the structure of the solutions of discrete-time algebraic Riccati Equation with singular closed-loop matrix.",
	journal="IEEE Transactions on Automatic Control",
	year="2004",
	pages="2049-2054",
	volume="AC-49(11)",
	issn="0018-9286"
}