Go4Expert - Finding Unique records in multiple tables

Hi:
I have this query to match Student ID in Results1 and Results2. And display the results
Now i want to modify it to search in Results3 and Results 4 table also?
How can i do it
Further R1 appears in all 4 Results tables. Can i Show the Max R1 vaule only in one column after searching ? instead to showing R1 from all tables??

Code:

SELECT Students.StudentID

     , Students.Fullname

     , Results1.R1 AS Results1_R1 

     , Results1.R2 AS Results1_R2

     , Results2.R1 AS Results2_R1

     , Results2.R2 AS Results2_R2    

  FROM (

       Students

LEFT OUTER

  JOIN Results1

    ON Results1.StudentID = Students.StudentID

       )

LEFT OUTER

  JOIN Results2

    ON Results2.StudentID = Students.StudentID