What is PMID, and what is DOI? I have just learned a little.
PMID is the serial number one paper had in the PUBMED. DOI is the address of one paper on net forever, just like the identification card of people. It won’t change with the alternations of the magzine and other things. You can find the paper always through its DOI.
Now I will show you a simple way to find PMID and DOI: first, find the paper in PUBMED; then click the butten “DISPLAY” on the top-left, choose “Medline” and “Apply”, the page will refresh atomatically; and you will see a lot of informations, you can see the PMID on the top, and you will find the “AID” on the bottom, it will show you the “DOI” or ‘PPI’.
As ‘PPI’, I’m not clear what it is, I guess it may be an another address for the paper. If I find the exact meaning of the ‘PPI’, I will add it in the paper.