Stopping formulas from changing when sorted
 

I'm trying to link two tables, adding two cells from one table to a cell in
another table, however I want to sort both tables (they're for motorsports
results).

My formula is currently =('Australia, Melbourne' 'Fernando
Alonso;')+('Australia, Melbourne' 'Lewis Hamilton;') but whenever it's sorted
the 'Fernando Alonso;' changes to 'Heikki Kovalainen;'

How can I stop it from changing when I sort the tables?