EcoSal Online is a continually updated Web resource based on the classic ASM Press print publication "Escherichia coli and Salmonella: Cellular and Molecular Biology" Author: Neidhardt. This project is intended primarily to serve the needs of the E. coli/Salmonella research community as a comprehensive archive of the entire corpus of knowledge about the enteric bacterial cell. It is expected to be of value also to all cellular and microbial biologists and to be a resource for advanced undergraduate and graduate instruction.

MEDLINE® is the United States National Library of Medicine's (NLM®) premier bibliographic database providing information from the following fields: Medicine, Nursing, Dentistry, Veterinary medicine, Allied health, Pre-clinical sciences. as well as information from international literature on biomedicine, including the following topics as they relate to biomedicine and health care: Biology, Environmental science, Marine biology, Plant and animal science, Biophysics, Chemistry. The database contains bibliographic citations and author abstracts from approx. 5,000 biomedical journals published in the United States and in 70 other countries. MEDLINE contains well over 13 million citations dating back to 1946. NLM uses a controlled vocabulary of biomedical terms to index articles, to catalog books and other holdings. MEDLINE’s controlled-vocabulary thesaurus contains Medical Subject Headings (MeSH®) to describe the subject of each journal article in the database. MeSH terms provide a consistent way of retrieving information that uses different terminology for the same concept. Within MEDLINE’s thesaurus, MeSH terms display hierarchically by category, with more specific terms arranged beneath broader terms.

Nature Publishing Group (NPG) is a publisher of high impact scientific and medical information in print and online. NPG publishes journals, online databases, and services across the life, physical, chemical and applied sciences and clinical medicine. The MPG subscription also covers article-processing charges for Max Planck authors in Nature journals. Further details are available on the MPDL website.