Here are some useful tips to search for a website you need, on this directory. Note, only the sites listed here will be shown.

Keyword search - Type a key word related to the company or institution you are looking for and once you click 'Go', the names of all the related firms listed here is shown. Some examples of various options possible are given below.
 

To get the firms dealing in only a specific product, e.g. Compaq computers, type 'compaq' and get the names of all the listed dealers of only Compaq.

You could also type the first alphabet in the name of the company to get all the companies with the names beginning in that alphabet.