You may be able to get more results by adjusting your search query.

• If you are trying to use Boolean operators, they must be ALL CAPS: (( ((practical guidebook) OR (practical guide)) to (((statistical OR statistical) OR (statistical OR statistical)) OR (statistical OR statistical)) AND epidemiology. ) OR ( practice guide to statistics AND epidemiology. ))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( ((practical guidebook) OR (practical guide)) to (((statistical OR statistical) OR (statistical OR statistical)) OR (statistical OR statistical)) and epidemiology. ) OR ( practice guide to statistics and epidemiology. ))~".
• Adding a wildcard symbol may retrieve word variants: (( ((practical guidebook) OR (practical guide)) to (((statistical OR statistical) OR (statistical OR statistical)) OR (statistical OR statistical)) and epidemiology. ) OR ( practice guide to statistics and epidemiology. ))*.