Gaya APA
Riddell, T. et al (1982).
Economics : a tool for understanding society [second edition] (2nd.ed.).
Reading,Massachusetts:
Addison-Wesley Publishing.
Gaya MLA
Riddell, Tom. et al.
"Economics : a tool for understanding society [second edition]".
2nd.ed.
Reading,Massachusetts:
Addison-Wesley Publishing,
1982.
Text.