@conference {,
	title = {Ultrasonic Signal Acquisition Module for Smartphone Indoor Positioning.},
	booktitle = {Emerging Technologies and Factory Automation, ETFA{\textquoteright}14 },
	year = {2014},
	month = {09/2014},
	pages = {1-4},
	publisher = {IEEE},
	organization = {IEEE},
	address = {Barcelona, Espa{\~n}a},
	isbn = {978-1-4799-4845-1/14},
	author = {A. Lindo and Mar{\'\i}a del Carmen P{\'e}rez and Ure{\~n}a, J. and Gualda, D and E. Garcia and Jos{\'e} Manuel Villadangos}
}
