On disc two, highlight [Navigation Options] and press 
[Enter]. Then enter the numbers [52579] (the U.S. 
theatrical release date for Alien, May 25, '79) to 
get the DVD production credits. 

On disc four, highlight [Navigation Options] and press 
[Enter]. Then enter the numbers [71886] (the U.S. 
theatrical release date for Aliens, July 18, '86) to 
get the DVD production credits. 

On disc six, highlight [Navigation Options] and press 
[Enter]. Then enter the numbers [52292] (the U.S. 
theatrical release date for Alien 3, May 22, '92) to 
get the DVD production credits. 

On disc eight, highlight [Navigation Options] and press 
[Enter]. Then enter the numbers [112697] (the U.S. 
theatrical release date for Alien Resurrection, 
Novenber 26, '97) to get the DVD production credits.