Perhaps you should try some spelling variations:
"big 198ais conference" » "big ais conference" (Expand Search), "big hbai conference" (Expand Search), "big soas conference" (Expand Search)
"big 1984 conference" » "big 1st conference" (Expand Search), "big 198ds conference" (Expand Search), "big 1981st conference" (Expand Search), "big 198ais conference" (Expand Search)
"pi 4 conference" » "pi ds conference" (Expand Search), "pi 1st conference" (Expand Search), "pi ais conference" (Expand Search), "pi _ conference" (Expand Search), "pi l conference" (Expand Search)

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

• Performing a fuzzy search may retrieve terms with similar spellings: (((("big 1984 conference") OR ("pi 4 conference"))) OR ("big 198ais conference"))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((\"big 1984 conference\") OR (\"pi 4 conference\"))) OR (\"big 198ais conference\"))".
• Removing quotes may allow a broader search: (((( big 1984 conference ) OR ( pi 4 conference ))) OR ( big 198ais conference )).
• Adding a wildcard symbol may retrieve word variants: (((("big 1984 conference") OR ("pi 4 conference"))) OR ("big 198ais conference"))*.