There is a new feature in the Business section of Reference USA. Under Custom Search, Special Selects there is a check box for "Web Address". This is currently limited to searching for companies that have web addresses. In order to use it you must have selected other criteria, such as Yellow Page heading or SIC code. After you create the search form, highlight "Web Address". This will limit your search to those businesses with web addresses. The "Select Web Address" option, which will allow you to search by specific web address, is not available yet.