Perhaps you should try some spelling variations:
"national investment treaties series" » "international investment treaties series", "capital investment treaties series", "national treatment treaties series", "national investment strategies series", "national investment activities series", "national investment incentives series"
"industrial development center series" » "industrial development case series", "industrial development agencies series", "industrial development center survey"

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

• Performing a fuzzy search may retrieve terms with similar spellings: (("national investment treaties series") or ("industrial development center series"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("national investment treaties series") OR ("industrial development center series")).
• Removing quotes may allow a broader search: (( national investment treaties series ) or ( industrial development center series )).
• Adding a wildcard symbol may retrieve word variants: (("national investment treaties series") or ("industrial development center series"))*.