Question: What is an ISSN, ISBN, DOI or PMID?
Books, Journals, and digital resources are given unique numbers that can be used to identify them and make finding them easier.
DOI (Digital Object Identifier) or a PMID (PubMed Identifier) is a unique number that has been assigned to a digital object, such as an article, book chapter, or data set.
If you have the DOI or PMID for something, it can help you get directly to the content.
ISSN stands for International Standard Serial Number. ISSN's have eight digits, and each is unique to a journal publication.
ISBN stands for International Standard Book Number. ISBN's have 10 or 13 digits, and each is unique to a book publication.