Referent is the true value of a word while the sense is the thought that the word or the sentence expresses. The phrase above has sense as it could mean the physical outlook of the earth surface but has not referent as the earth is spherical and not flat as the sentence claims.
Primary resource means when it come directly from the person who witness the situation for example in a court Room there’s a typer who types every word that’s being said in the court room
