Documentation search can be conducted online through the Internet or using CD-ROM. The systems for documentation search through the Internet network are called “ERL”, which is provided by SilverPlatter Information, Inc., and “OvidNet”, provided by Ovid Technologies, Inc. Another system is Client/Server. Since features depend on the companies providing the service, one must actually obtain as much information as possible from users or agencies who have already tried them. It is a wonderful thing to search the databases. Lately network-oriented versions have emerged from the Internet system. One of them is U-Gate. It is a system which takes advantage of database documentation techniques. One can search for documentation by accessing a provider and using a browser. Documentation search systems such as this are getting more popular as the infrastructure improves. After contracting with companies in the cordial Internet environment, one can search for documentation on MEDLINE from a reference, link it to the MEDLINE database and link the search results to a full text.