In conclusion, PubMed citations come from 1) MEDLINE indexed journals, 2) journals/manuscripts deposited in PMC, and 3) NCBI Bookshelf. Both MEDLINE and other PubMed citations may have links to full-text articles or manuscripts in PMC, NCBI Bookshelf, and publishers' Web sites. If you limit your PubMed search to MeSH controlled vocabulary or the MEDLINE subset, you will see only MEDLINE citations in your results.

The MEDLINE database is directly searchable from NLM as a subset of the PubMed® database as well as through other numerous search services that obtain the data from NLM’s Data Distribution program

In addition to the comprehensive journal selection process, what sets MEDLINE apart from the rest of PubMed is the added value of using the NLM controlled vocabulary, Medical Subject Headings (MeSH®), to index citations.

MEDLINE is the largest subset of PubMed

PubMed citations are created for content not already in the MEDLINE database. Some PMC content, such as book reviews, is not cited in PubMed.

Un estudio de tres investigadores españoles y que ha sido publicado en la revista científica Science Direct ha revelado que la mayoría del cannabis que se vende en Madrid está contaminado con restos fecales. En concreto, se trata de la bacteria E.coli y del hongo ‘Aspergillus’, que está asociado a provocar problemas respiratorios.

The NLM Catalog provides access to NLM bibliographic data for journals, books, audiovisuals, computer software, electronic resources and other materials. Links to the library's holdings in LocatorPlus, NLM's online public access catalog, are also provided.