Find/Return Unique Data

i have 2 different spreadsheets
sheet 1 and sheet 2
in sheet 1 i have suppouse following data


Name-- Prod. --value --year


-- a -- 24 -- 100 -- 2004

-- b -- 26 -- 240 -- 2004

-- a -- 33 -- 120 -- 2004

-- a -- 21 -- 200 -- 2004

-- c -- 26 -- 240 -- 2004

-- b -- 33 -- 120 -- 2004
-- d -- 24 -- 100 -- 2004

in sheet 2

Name -- Prod. -- value -- year

-- a -- 24 -- 100 -- 2005
-- d -- 26 -- 240 -- 2005
-- a -- 33 -- 120 -- 2005
-- e -- 26 -- 240 -- 2005
-- a -- 21 -- 200 -- 2005
-- c -- 26 -- 240 -- 2005
-- d -- 24 -- 100 -- 2005

in this situation i want to find out the dropouts of sheet 1. (that persons which are not present the sheet 2)
how can i compare these sheets?
in this case i want the result as

-- Name -- Prod. -- value -- Year
-- b -- 26 -- 240 -- 2004
-- b -- 33 -- 120 -- 2004