Perhaps you should try some spelling variations:
"aids medicines research : july 2008" » "aids medicine research : july 2008", "aids medical research : july 2008", "aids policies research : july 2008", "making medicines research : july 2008", "aids medicines research : july 2013", "aids medicines research : july 2012", "aids medicines research : july 2020"
"aids vaccine research : july 2007" » "aids medicine research : july 2007", "aids vaccine research : july 2013", "aids vaccine research : july 2012", "aids vaccine research : july 2020"

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: (("aids vaccine research : july 2007") OR ("aids medicines research : july 2008"))~.
• Removing quotes may allow a broader search: (( aids vaccine research : july 2007 ) or ( aids medicines research : july 2008 ))~.
• Adding a wildcard symbol may retrieve word variants: (("aids vaccine research : july 2007") or ("aids medicines research : july 2008"))*.