English Materials by Torsten Schulz
  • Wikipedia
    The free-content encyclopedia that anyone can edit. There are also other national editions, e.g. German.

  • Encyclopædia Britannica
    Well, who doesn't know about it ...

  • Encarta Worldwide
    There you will find all national editions online, e.g. USA, UK, Australia, etc.

  • xrefer
    Calls itself "the web's reference engine". xrefer contains encyclopedias, dictionaries, thesauri & books of quotations. All entries are cross-referenced.