Advanced Search — Use this search option to create search queries using field tags and set combinations. Each search term must be prefaced by a field tag, and search terms must be joined by Boolean operators.

In this example, we want to refine our search for records about soil respiration. We do another search for records indexed with the CABICODE for soil chemistry and the CAS Registry® number for carbon dioxide. We then combine the results of this set with the results of set one using the AND Boolean operator to create set #3.