NCC Education Services. (1999). Systems Analysis Techniques. NCC Education Services.
Citazione stile Chigago Style (17a edizione)NCC Education Services. Systems Analysis Techniques. Manchester: NCC Education Services, 1999.
Citatione MLA (9a ed.)NCC Education Services. Systems Analysis Techniques. NCC Education Services, 1999.
Attenzione: Queste citazioni potrebbero non essere precise al 100%.