xpath=(//a[@class='addthis_button'])[last()-2]
xpath=(//a[@class='addthis_button'])[last()]
xpath=(//a[@class='addthis_button'])[position()=2]
//a[contains(@class, concat("addthis_button_compact", " at300m"))]
More reference : http://shanmugavelc.blogspot.com/2011/11/selenium-css-locators.html
