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)
"pi 1984 conference" » "pi 1st conference" (Expand Search), "pi 198ds conference" (Expand Search), "pi 1981st conference" (Expand Search), "pi 198ais conference" (Expand Search), "ali 1984 conference" (Expand Search), "pei 1987 conference" (Expand Search)
"big 4 conference" » "big ds conference" (Expand Search), "big 1st conference" (Expand Search), "big ais conference" (Expand Search), "bi 4 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 4 conference") OR ("pi 1984 conference"))) OR ("big 198ais conference"))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((\"big 4 conference\") OR (\"pi 1984 conference\"))) OR (\"big 198ais conference\"))".
• Removing quotes may allow a broader search: (((( big 4 conference ) OR ( pi 1984 conference ))) OR ( big 198ais conference )).
• Adding a wildcard symbol may retrieve word variants: (((("big 4 conference") OR ("pi 1984 conference"))) OR ("big 198ais conference"))*.