How to choose or add another source to my search?

To switch the sources for your search click the cog icon below the search form. If you can't see any cog icon, please perform a search and try again to find the cog icon. You will find it direcly below the input field and next to the search button. Found it? Then you need to click it and select the sources you want to search on. The selected sources will be darker then the ones you haven't selected.