This guide is designed to be a learning tool. It is not a substitute for The Chicago Manual of Style OR your instructor's requirements.
Many publishers are now using the Digital Object Identifier (DOI) System -- commonly referred to as DOI or DOI numbers -- to provide unique and persistent identifiers for journal articles.
The 16th edition of the Chicago Manual of Style incorporates DOI numbers for journal articles if they are available.
EXAMPLE OF DOI NUMBER:
Here are some suggestions on where to look for a DOI for an article or e-book that you wish to cite:
Keep in mind that not all journal publishers use the DOI System.