Perhaps you should try some spelling variations:
optics research » haptics research, omics research, robotics research
option research » opinion research, action research, actions research
multi optics » multi omics, multi omic, multi pairs
multi option » multi location, multi population, multi ratios
july 2006 » july 2008, july 2007, july 2009

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( multi optics research : july 2006 ) or ( multi option research : july 2006 ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( multi optics research : july 2006 ) OR ( multi option research : july 2006 )).
• Adding a wildcard symbol may retrieve word variants: (( multi optics research : july 2006 ) or ( multi option research : july 2006 ))*.