1. Magnetic sensors for navigation and security applications;Ripka,2006
2. M.J. Caruso, L.S. Withanawasam, Vehicle Detection and Compass Applications using AMR Magnetic Sensors, http://www.ssec.honeywell.com/magnetic/mark_det.html
3. Friis formula for amplifiers in cascade: http://www.internationaleventconnection.com/mtt14/friis.html.
4. Datasheet of the magnetic sensor AB001-02 from NVE Corporation, http://www.nve.com/Downloads/analog_catalog.pdf.
5. Basics of analog differential filters;ramon;IEEE Trans. Instrum. Meas.,1996