Referer or Referrer: How To spell?
The word Referer is misspelled against Referrer, a noun meaning "One who refers."
Referrer has double "rr" is mispronounced as "r"Remember double 'RR' in between the strings refe & er which should not be misspelled with single 'R'
Wrong Spelling:  refe-r-er  Correct Spelling:  refe-rr-er 
Explore spell check of Referrer to spell without errors.