Until this point searches of the ChemSpider database have only been possible across all content, over 10 million compounds. The ability to narrow the search has now been introduced by allowing one or more individual data sources to be selected for the search. In order to perform a search based only on selected data sources simply enter the Advanced Search Mode and select the Data Sources checkbox. The Selection Box shown below will be displayed. Usage is self-explanatory. Enjoy…we welcome any feedback.