PubMed PMC Bookshelf Search funktioniert nicht

MEDLINE is the largest component of PubMed and consists primarily of citations from journals selected for MEDLINE; articles indexed with MeSH (Medical Subject Headings) and curated with funding, genetic, chemical and other metadata.  PubMed comprises more than 30 million citations for biomedical literature from MEDLINE, life science journals, and online books.  It does not include full-text journal articles; however, links to the full text are often present when available from other sources, such as the publisher's website or PubMed Central (PMC).  Citations in PubMed primarily stem from the biomedicine and health fields, and related disciplines such as life sciences, behavioral sciences, chemical sciences, and bioengineering.  Citations may include links to full-text content from PubMed Central and publisher web sites. - This app is run by an individual and has nothing to do with NCBI.  PubMed is a free resource supporting the search and retrieval of biomedical and life sciences literature with the aim of improving health–both globally and personally.  Citations for PubMed Central (PMC) articles make up the second largest component of PubMed.  The final component of PubMed is citations for books and some individual chapters available on Bookshelf.  The PubMed database contains more than 30 million citations and abstracts of biomedical literature.  PMC is a full-text archive that includes articles from journals reviewed and selected by NLM for archiving (current and historical), as well as individual articles collected for archiving in compliance with funder policies.  Available to the public online since 1996, PubMed was developed and is maintained by the National Center for Biotechnology Information (NCBI), at the U. S.  National Library of Medicine (NLM), located at the National Institutes of Health (NIH).  Bookshelf is a full-text archive of books, reports, databases, and other documents related to biomedical, health, and life sciences.