Academic Citations

Digital Object Identifiers (DOIs)

What is a DOI?

A DOI (Digital Object Identifier) is a unique, permanent identification number assigned to academic publications. DOIs provide a standardized way to locate documents regardless of where they are stored online.

DOI Formatting Requirements

Required Format: https://doi.org/xxxxx

Alternative Acceptable Format: http://doi.org/xxxxx

DOI Usage Rules

1. Always use DOI when available - If a publication has a DOI, use the DOI instead of a URL
2. Copy and paste directly - Copy DOIs exactly from the source to avoid errors
3. No additional text - Do not use "Retrieved from" or "Accessed from" before a DOI
4. No period after DOI - Do not add punctuation after the DOI
5. Live hyperlinks preferred - Present DOIs as clickable links when publishing online

Display Options

• Use default hyperlink display (typically blue, underlined text), OR
• Use plain text format without underlining
• Maintain consistency throughout your document

URLs (Uniform Resource Locators)

When to Use URLs

Use URLs only when:

• No DOI is available for the publication
• The work is from a website that does not assign DOIs

URL Formatting Requirements

1. Complete URL required - Copy the full web address from your browser
2. No additional text - Do not use "Retrieved from" before URLs
3. No period after URL - Do not add punctuation after the URL
4. Maintain exact formatting - Preserve all characters and spacing exactly
5. Live hyperlinks preferred - Make URLs clickable when publishing online

URL Guidelines

• Use the most direct, stable URL available
• Avoid URLs that require login credentials
• Test URLs before finalizing citations to ensure they work correctly

Special Cases

Database Sources

If accessing articles through research databases:

• Use the DOI if available (preferred method)
• If no DOI exists, do not include database URLs or database names
• Treat the reference as if citing a print version

Retrieval Dates

Generally, do not include retrieval dates. Only include retrieval dates when:

• The content is not archived
• The content may be updated or changed over time

Formatting in Word Processors

• URLs and DOIs may break across lines - allow natural line breaks
• Do not manually insert hyphens in URLs or DOIs
• Break before punctuation marks when possible

Quick Reference

Common Errors to Avoid

• Adding periods after DOIs or URLs
• Using "Retrieved from" before DOIs or URLs
• Including database-specific URLs that require login
• Manually typing DOIs instead of copying/pasting
• Using outdated DOI formats (e.g., dx.doi.org)

More Resources

• APA DOI & URL Guidelines
• URL Usage Rules
• MeSH Terms