README: Attribute Reference Table
| Attribute Name | Type | Optional | Notes |
| pmid | String | No | Primary PubMed Identifier |
| title | String | No | Always present |
| authors | String | No | Author list |
| journal | String | No | Journal name |
| pubDate | Date | No | Publication date |
| abstract | String | Yes | Missing in legacy articles |
| fullTextAvailable | Boolean | Yes | Based on PMC presence |
| doi | String | Yes | Not always assigned |
| pmcid | String | Yes | Open access PMC ID |
| volume | String | Yes | Volume number |
| issue | String | Yes | Issue number |
| pages | String | Yes | Page range |
| keywords | String | Yes | Publisher-supplied tags |
| affiliations | String | Yes | Author affiliations |
| funding | String | Yes | Funding disclosures |
| conflictOfInterest | String | Yes | COI statements |