Multiple Criteria - SUMIF

I'm about to commit computer homicide if I don't get this. I've been working on this for the past two hours surfing the web and trying out solutions from different sites but I'm about to blow. I'm trying to link to a spreahsheet and sum up data with different criteria. If the date and name of person appear in the separate columns then the numbers are totaled. Please help!!!

Have no problem with this formula: =SUMIF('Sheet1'!J2:J91,"10/1/2007",'Titles Data'!E2:E91)

However, I need something that will function that is similar to this: =SUMIF('Sheet1'!J2:J91 AND 'Sheet1'!A2:A91,"2/1/2007" AND "Keri",'Sheet 1'!E2:E91)

I've also tried

=SUMIF('Titles Data'!J2:J91 AND A2:A91,"2/1/2007" AND "Keri",'Titles Data'!E2:E91)

=SUM(IF('Titles Data'!J2:J250="2/1/2007,IF('Titles Data'!A2:250="Keri"),'Titles Data'!E2:E91))

=SUM(IF(A1:A3=1,IF(B1:B3>29,1,0),0))

=SUMPRODUCT(--('Titles Data'!j2:J91=2/1/2007), --('TitlesData'!A2:A91=Keri), E2:E91)

=SUMPRODUCT(('Titles Data'!J2:J91="2/1/2007")*('Titles Data'!A2:A91="Keri")*('Titles Data'!E2:E91))

=Sum(If('Titles Data'!J2:J91="2/1/2007",if('Titles Data'!A2:A91="Keri",'Titles Data'!E2:E91)))

=SUM(IF('Titles Data'!J2:J250=2/1/2007 AND 'Titles Data'!A2:A250=Keri,Titles Data'!E2:E91)

=SUM(IF('Titles Data'!J2:J250="2/1/2007" AND 'Titles Data'!A2:A250="Keri",'Titles Data'!E2:E91,0)

=SUMPRODUCT('Titles Data'!E2:E91,(IF('Titles Data'!J2:J250,"2/1/2007"))*(IF('Titles Data'!A2:A250,"Keri"))

=SUM(('Titles Data'!E2:E9)*(IF('Titles Data'!J2:J250,"2/1/2007"))*(IF('Titles Data'!A2:A250,"Keri")))

None of these have worked