You can use a refactoring feature to locate namespaces or units. If you are using Delphi, you can use the Find Unit command to locate and add units to your code file based on objects in your code. 

The Find Unit dialog appears when you select an object name and select the Find Unit command. The import operation attempts to find the appropriate unit containing the definition of the selected object, and then adds the selected unit to the uses clause. You can select multiple units to add to the uses clause.