Wenwen Liang Mingxin Qin Mingke Jiao Hao Yang Ke Li Teng Jiao Liyuan Bai Wenyong Wang Phase Detection Based on the Lock-in Amplifier SR844 and Experiments of Brain Neuron Cells in MIT System. 638-642 2008 BMEI (1) http://doi.ieeecomputersociety.org/10.1109/BMEI.2008.103 conf/bmei/2008-1 db/conf/bmei/bmei2008-1.html#LiangQJYLJBW08