Perhaps you should try some spelling variations:
options research » actions research, optics research, operations research
ii national » 3 national, 2 national, 4 national
i national » 3 national, 2 national, 4 national
i options » 4 options, 2 options, iii options
july 2020 » july 2013, july 2012
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: (( i options research : july 2020 ) or ( ((i national) or (ii national)) research : july 2006 ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( i options research : july 2020 ) OR ( ((i national) OR (ii national)) research : july 2006 )).
• Adding a wildcard symbol may retrieve word variants: (( i options research : july 2020 ) or ( ((i national) or (ii national)) research : july 2006 ))*.