10th smallest value in multiple worksheets

I was using the following formula to determine the 10th deal that a rep wrote:

=IF(O4="","",IF(COUNTIF('Compliance 5-1-08 to 1-14-09'!$B$2:$B$7957,C4)<10,"",SMALL(IF('Compliance 5-1-08 to 1-14-09'!$B$2:$B$7957=C4,'Compliance 5-1-08 to 1-14-09'!$O$2:$O$7957),10)))

At the time, all of the data was on one worksheet "'Compliance 5-1-08 to 1-14-09'". However, that report now has a different format, and so now all of the new data in on a new worksheet "Compliance". I am trying to modify the formula to accomadate the two sets of data. I got the first part of the formula changed, but I'm not sure how to modify the second part with the SMALL function. Does anyone have any suggestions?

=IF(O4="","",IF(SUM(COUNTIF('Compliance 5-1-08 to 1-14-09'!$B$2:$B$7957,C4),(COUNTIF(Compliance!$B$2:$B$200,C4)))<10,"",SMALL(IF('Compliance 5-1-08 to 1-14-09'!$B$2:$B$7957=C4,'Compliance 5-1-08 to 1-14-09'!$O$2:$O$7957),10)))