If you are searching more than one database, on the Refine Search sub-tab the limiters common to the databases appear under the Limit your results heading. If you select any of the common limiters, they are applied to all databases you are searching. A limiter will appear in the common limiters section only if it is available in all the databases you selected. If a limiter is available in three of four databases you selected, it will be displayed in the special limiters section of those three databases. If all databases share the same special limiters, they will all appear in the common limiters section.
The database-specific limiters appear under the heading Special limiters for: Database Name. (e.g., Special limiters for: Academic Search Premier) If you select a special limiter, it is applied only to the database under which it appears. For example, you might select the Publication type limiter below Academic Search Premier, and need to select it again below Newspaper Source.