Voltage-dependent excitation profiles of pyridine adsorbed on a silver electrode http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFN-44XDGM0-C&_user=2324792&_rdoc=1&_fmt=&_orig=search&_sort=d&_docanchor=&view=c&_acct=C000056916&_version=1&_urlVersion=0&_userid=2324792&md5=e9f15357efc4a2a05afd733402a83a23