Gaya APA

WHITTEN, J, L. et al (1990). System analysis & design methods (ed. 2.; cet. 1). SINGAPORE: RICHARD D. IRWIN.

Gaya MLA

WHITTEN, Jeffrey, L.. et al. "System analysis & design methods". ed. 2.; cet. 1 SINGAPORE: RICHARD D. IRWIN, 1990. Text.