citation-management - SKILL.md Agent Skill

name: citation-management description: Use when adding citations to a .bib file, importing references by DOI, cleaning a bibliography, detecting duplicate entries, or normalizing citation keys. Uses direct .bib manipulation with CrossRef API for metadata resolution — no external tool dependencies.

Citation Management

Overview

This skill manages the project's references.bib directly, using the CrossRef API to resolve DOIs into complete BibTeX entries. It does not require Zotero, any external CLI, or any desktop application. Everything happens through standard tools: curl (or equivalent HTTP client) and text editing of the .bib file.

When to Use

"Add this paper to the bibliography"
"Import this DOI"
"Clean up the .bib file"
"Are there duplicates in my references?"
"Fix the citation keys"
Before submission: validate that all cited papers have complete entries

Mandatory Steps

Resolve every DOI via CrossRef. Call https://api.crossref.org/works/{doi}. Extract: title, full author list, year, journal, volume, issue, pages, publisher, and DOI. Do not invent fields missing from the API response — leave them out instead.
Generate a BibTeX entry with complete fields. Required for articles: author, title, year, journal, volume, pages, doi. For books: author (or editor), title, year, publisher, doi. For chapters: add booktitle and editor.
Citation key format: FirstAuthorLastnameYear, e.g., Santos2024. Disambiguate collisions with lowercase letters: Santos2024a, Santos2024b. Strip accents and non-ASCII characters from the key — BibTeX tooling does not always handle Unicode in keys.
Check for duplicates before adding. Duplicate definition: same DOI, OR same title (case-insensitive, normalized whitespace) AND same first author AND same year. If duplicate, skip and report the existing key.
Keep references.bib sorted alphabetically by citation key. Sort after every insert so the file stays stable across commits.
Preserve existing entries. Do not rewrite fields of existing entries unless the user explicitly asks. Append new entries in the correct sorted position.

CrossRef API Example

curl -s 'https://api.crossref.org/works/10.1257/aer.84.4.772' \
  | jq '.message | {title, author, issued, container-title, volume, page, DOI}'

The response provides all fields needed to build a complete BibTeX entry. Parse the author array to extract each author's given and family name, then format as Family, Given and Family2, Given2.

BibTeX Entry Template

@article{CardKrueger1994,
  author  = {Card, David and Krueger, Alan B.},
  title   = {Minimum Wages and Employment: A Case Study of the Fast-Food Industry in New Jersey and Pennsylvania},
  journal = {American Economic Review},
  year    = {1994},
  volume  = {84},
  number  = {4},
  pages   = {772--793},
  doi     = {10.1257/aer.84.4.772}
}

Use braces for titles that contain words requiring specific capitalization (e.g., proper nouns, acronyms): title = {The {DiD} Approach to Causal Inference}. Use double hyphens for page ranges (772--793).

Anti-Patterns

BibTeX entries with missing DOIs
Inconsistent citation keys in the same file (mix of santos2024 and Santos_2024)
Duplicate entries — same DOI appearing with different keys
Entries with "et al." in the author field instead of the full author list
Using braces incorrectly to preserve capitalization (either too many or too few)
Editing an existing paper's entry without being asked
Adding metadata from memory instead of resolving via CrossRef
Leaving the .bib file unsorted after insertion

Verification Before Completion

Every new entry has a DOI field
Every entry has the full author list, not et al.
Citation keys follow the AuthorYear[letter] format consistently
No duplicates detected (by DOI or by title+author+year)
File sorted alphabetically by citation key
Existing entries untouched unless explicitly modified
Page ranges use double hyphens (--)