@article {aja2006fuzzy,
	title = {Fuzzy feedback system analysis using transition matrices},
	journal = {Fuzzy sets and systems},
	volume = {157},
	number = {4},
	year = {2006},
	pages = {516{\textendash}543},
	publisher = {Elsevier},
	author = {Santiago Aja-Fern{\'a}ndez and Carlos Alberola-Lopez}
}
