Perhaps you should try some spelling variations:
"multiple access research : july 2008" » "multiple success research : july 2008", "multiple assess research : july 2008", "multiple process research : july 2008", "multiple access research : july 2013", "multiple access research : july 2012", "multiple access research : july 2020"
"multi option research : july 2006" » "multi opinion research : july 2006", "multi action research : july 2006", "multi optics research : july 2006", "multi location research : july 2006", "multi population research : july 2006", "multi ratios research : july 2006", "multi option research : july 2007", "multi option research : july 2009", "multi option research : july 2013"

Try widening your search to All Fields.

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

• Performing a fuzzy search may retrieve terms with similar spellings: (("multiple access research : july 2008") or ("multi option research : july 2006"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("multiple access research : july 2008") OR ("multi option research : july 2006")).
• Removing quotes may allow a broader search: (( multiple access research : july 2008 ) or ( multi option research : july 2006 )).
• Adding a wildcard symbol may retrieve word variants: (("multiple access research : july 2008") or ("multi option research : july 2006"))*.