Databases & On-Line Reference Books

PubMed
(via CU)
This gigantic database has replaced MedLine, as well as other NLM databases such as BioEthicsLine (see below).  It contains articles only.
In order to facilitate
bioethics searches in PubMed, one can limit one's search to bioethics articles only.  Click "Limits" and then "Subset" and choose "Bioethics".  To search historical articles, limit to "History of Medicine".
LocatorPlus NLM Database of books, journals, and audiovisuals.
EthicsShare EthicsShare allows searching for a wide variety of information types that include articles, blogs, books, digital objects, popular literature
Belit

BELIT (Bioethics Literature Database) is a multi-lingual (German, French and English) database hosted by the German Reference Centre for Ethics in the Life Sciences (DRZE). BELIT contains over 320,000 bibliographic records for monographs, journal and newspaper articles, legal documents, reports and unpublished documents.

ETHX A bibliographic database on bioethics and professional ethics. Contains nearly 100.000 references.  Journal articles, book chapters, bills, laws, court decisions, reports, books, audio-visuals, and news articles relating to bioethics and professional ethics. Contains some non-English references
EuroEthics This recent database is the European complement of BioethicsLine and contains non-English publications. Limitation: Still very small.
Global Ethics Observatory

UNESCO’s Global Ethics Observatory (GEObs) consists of six related databases available in UNESCO’s six official languages: Arabic, Chinese, English, French, Russian and Spanish. Focus on bioethics and ethics of science and technology.

BioethicsLine This database was part of the US National Library of Medicine (NLM) and focused on English language bioethics literature, starting in 1973. Unfortunately, NLM  has stopped expanding this database as of December 2000.  Part of the database (articles) has been merged into the new NLM PubMed database (see above). Another part (books and audiovisuals) has been moved to LocatorPlus (see above).
History of medicine The sperare HistLine, that is, the History of Medicine Database, that was maintained by the US National Library of Medicine (NLM) and focused on English language bioethics literature has been discontinued. Part of the database (articles) has been merged into the new NLM PubMed database (see above). Another part (books and audiovisuals) has been moved to LocatorPlus (see above).
For other historical materials on-line, including manuscripts and
images, visit the webpage of the NLM History of Medicine Division.
Philosopher's Index This database of philosophical literature covers publications of many kinds and in many languages. However, it is not freely accessible via the net. Many university libraries subscribe to it on CD-Rom or in book form.
Encyclopedia of Bioethics Third edition of the encyclopedia (first published in 1978).  Citations can be exported into reference software.