shopcade:

referer = function(v){

  v[str_detect(v,'google')]='google'
  v[str_detect(v,"facebook")]="facebook"
  v[str_detect(v,"elle")]="elle"
  v[str_detect(v,"pinterest")]="pinterest"
  v[str_detect(v,"yandex")]="yandex"
  v[str_detect(v,"bing")]="bing"
  v[str_detect(v,"yahoo")]="yahoo"
  v[str_detect(v,"instagram")]="instagram"
  v[str_detect(v,"baidu")]="baidu"
  v[str_detect(v,"aol.")]="aol"
  v[str_detect(v,"doubleclick")]="doubleclick"
  v[str_detect(v,"wheretoget")]="wheretoget"
  v[str_detect(v,"t.co")]="twitter"
  v[str_detect(v,"public")]="public"
  v[str_detect(v,"duckduckgo")]="duckduckgo"
  v[str_detect(v,"youtube")]="youtube"
  v[str_detect(v,"tumblr")]="tumblr"
  v[str_detect(v,"sogou")]="sogou"
  v[str_detect(v,"ecosia")]="ecosia"
  v[str_detect(v,"adroll")]="adroll"
  v[str_detect(v,"(tumblr|t.umblr)")]="tumblr"
  v[str_detect(v,"(shopcade)")]="shopcade"
  return(v)
}