油井緋色;1676038 said:Also, @RockerGuy
If they both really do have PhDs, they don't need references: THEY GET REFERENCED. Same goes for MDs...but not as much as PhDs.
I don;t know what field you're in, but in my field, everybody needs to reference. That included one of my ex-boss who had 200 research articles to his name.
You might not need to reference anything if you are casually discussing something or if a doctor is speaking to a patient. But in a scientific community, 99.999999% of articles have a reference at the back. Pick up any journal and look at the back there should be a reference section. Here are a couple with references that relate to what is being discussed:
http://iv.iiarjournals.org/content/19/2/417.full.pdf
http://www.scielo.br/scielo.php?pid=S1516-89132009000500021&script=sci_arttext