Perhaps you should try some spelling variations:
"initial investment treaties series" » "initial investment strategies series", "initial investment activities series", "initial investment incentives series", "national investment treaties series", "capital investment treaties series", "initial investment textiles series", "initial investment theories series", "initial investment forestiers series"
"industrial development sector survey" » "industrial development history survey", "industrial development series survey", "industrial development social survey"

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

• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"initial investment treaties series\") OR (\"industrial development sector survey\"))~".
• Removing quotes may allow a broader search: (( initial investment treaties series ) OR ( industrial development sector survey ))~.
• Adding a wildcard symbol may retrieve word variants: (("initial investment treaties series") OR ("industrial development sector survey"))*.