@inbook { santos14,
	chapter = {On a Question by Markus Seidel},
	keywords = {Miscellaneous;},
	pages = {159-172},
	publisher = {Springer Basel},
	series = {Operator Theory, Operator Algebras and Applications},
	title = {On a Question by Markus Seidel},
	volume = {242},
	year = {2014},
	author = {Pedro Santos and Davor Dragičević and Guida Preto and Marcin Szamotulski}
}