Perhaps you should try some spelling variations:
"teaching positions research : july 2011" » "teaching operations research : july 2011", "teaching opinion research : july 2011", "teaching visiting research : july 2011", "teaching positions research : july 2013", "teaching positions research : july 2012", "teaching positions research : june 2011"
"call options research : july 2006" » "call operations research : july 2006", "call action research : july 2006", "call opinion research : july 2006", "call option research : july 2006", "real options research : july 2006", "call options research : july 2013", "call options research : july 2012"

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

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• Removing quotes may allow a broader search: (( teaching positions research : july 2011 ) OR ( call options research : july 2006 ))*.