APA
(1999). Operating System 2. Salcedo St. Legaspi Village Makati City Manila: System Technology Institute, Inc.
Chicago
1999. Operating System 2. Salcedo St. Legaspi Village Makati City Manila: System Technology Institute, Inc.
Harvard
(1999). Operating System 2. Salcedo St. Legaspi Village Makati City Manila: System Technology Institute, Inc.
MLA
Operating System 2. Salcedo St. Legaspi Village Makati City Manila: System Technology Institute, Inc. 1999.