A wealth of data as well as software that could not be provided within this book or the enclosed CD-ROM is available via the Internet and the World Wide Web. We have, therefore, compiled a set of useful URL resources with a focus on those data that require frequent updates. All addresses may conveniently be accessed via the hyperlinks given below. It is emphasized, however, that the given list is in no way comprehensive and that server names and files are subject to changes without further notice.
© O. Montenbruck, E. Gill